Argued April 4, 2013
Appeal from the United States District Court for the Northern District of Illinois, Eastern Division. No. 08 c 4006 — Gary S. Feinerman, Judge.
Before Manion, Tinder, and Hamilton, Circuit Judges.
Hamilton, Circuit Judge.
On May 9, 2007, Brandon Stollings lost an index finger and portions of other fingers in a table saw accident. Stollings sued the saw manufacturer, Ryobi Technologies, alleging that Ryobi defectively designed the saw because it failed to equip the saw with either of two safety features: a riving knife—a small blade that holds the cut in the wood open to prevent kickbacks—and automatic braking technology—a safety system that automatically stops the saw blade upon contact with human tissue. Stollings contends either safety feature would have prevented the accident. A jury returned a verdict in favor of Ryobi. Stollings has appealed.
Stollings argues that the district court made three reversible errors: (1) failing to stop Ryobi's counsel from arguing to the jury that Stollings's counsel brought the case as part of a joint venture with the inventor of the automatic braking technology to force saw manufacturers to license the technology, and admitting hearsay evidence to support this improper argument; (2) excluding the testimony of one of Stollings's expert witnesses; and (3) giving two erroneous jury instructions. We find that Ryobi's joint venture argument was improper and prejudicial, so we vacate the judgment and remand for a new trial. Because the remaining issues are likely to resurface if the case is retried, we address them and conclude that the court erred in excluding the expert testimony and in giving the jury a sole proximate cause instruction where Ryobi was not asserting a comparative fault defense or blaming a third party.
I. The Improper Attack on Counsel's Motives
A. The Accident and Power Saw Safety
We address first Ryobi's improper attack at trial on the motives of plaintiff's counsel, which requires us to provide the background on the accident and power saw safety. Stollings was injured while operating a Ryobi Model BTS20R table saw. The immediate cause of the injury was a common woodworking hazard known as a kickback. A kickback occurs when the kerf, the gap in the wood created by a saw's cut, closes around the saw blade in such a way that the force of the spinning blade throws the wood back at the user. If the saw operator is holding onto the wood, the unexpected movement can sometimes force the operator's hand into the spinning saw blade. This is what happened to Stollings.
Saw manufacturers include safety features to help protect users from kickback injuries. Ryobi equipped the saw with a "3-in-1" guard safety system. This safety system has three components: a splitter, anti-kickback pawls, and a blade shield. The splitter is a piece of plastic that rests behind the saw blade to prevent the kerf from closing around the saw. The anti-kickback pawls are serrated pieces of metal attached to the sides of the splitter that rest on the wood as it moves through the cut to prevent the wood from moving backwards. And the blade shield is a piece of plastic that covers the top of the blade to prevent the user's hands from coming into contact with the blade. This system complied with the applicable guarding standards published by Underwriters Laboratory—a private company that sets industry safety standards—and the applicable federal Occupational Safety and Health Administration regulations.
The 3-in-1 system is effective at reducing injuries when used correctly, but it has shortcomings. The principal problem is that many saw users deliberately disable the 3-in-1 guard system. There are two reasons for this. The plastic guard makes certain cuts more difficult to complete, and the guard can become clouded by sawdust and other material, thus obstructing the user's view of the saw blade as it cuts. The 3-in-1 system is also interconnected. When a user removes the guard, he must also remove the splitter and the anti-kickback pawls, leaving the saw blade without any kickback protection. That is what Stollings did. Despite warnings on the saw about the dangers of operating the saw without the guard, Stollings removed the guard and operated the saw without the safety protection. Before a reader concludes that this fact decides the case, though, we should note that Ryobi's former chief engineer testified that he had removed the 3-in-1 system on his own home saw and had instead installed a riving knife.
The jury heard evidence that Ryobi could have equipped its saw with two alternative safety features. The first is a riving knife, which is a cheap piece of metal or plastic similar to a splitter. Like a splitter, a riving knife rests behind the blade and holds the kerf open. Unlike the splitter in the 3-in-1 guard system, a riving knife is typically positioned closer to the saw blade, making it more effective at preventing kickbacks. Most important, it is independent of the guard system, so the user has no reason to remove it.
The second additional safety feature is an automatic braking system, colorfully known as flesh detection technology. The automatic braking system prevents injury by stopping and retracting the blade at the moment the blade contacts flesh. The technology works by detecting the human body's electrical current. When an operator's flesh contacts the blade, the body's electrical current triggers the safety system, which applies a brake and retracts the blade beneath the cutting surface. The saw stops within a few milliseconds, fast enough in most cases to leave the operator with only a minor, superficial wound. The technology, however, is not cheap. It would add somewhere between $50 and $150 to the cost of a table saw.
Stephen Gass developed the automatic braking system in 1999. Gass patented the technology and then attempted to license it to table saw manufacturers, including Ryobi. Gass and Ryobi entered negotiations over a licensing agreement, but the negotiations fell through and Ryobi never licensed Gass's technology. Stollings maintains that Ryobi and other manufacturers decided not to license Gass's technology for fear of product liability exposure on saws that did not have the technology. Ryobi contends Gass's terms were unreasonable and the technology was too expensive and unproven. In 2005, Gass founded a competing company named SawStop to manufacture and sell table saws that include his automatic braking system. Gass testified at trial as one of Stollings's expert witnesses about the feasibility and effectiveness of the automatic braking system. He did not ask for or receive compensation for his testimony.
B. The Trial Attack on Plaintiff's Counsel
In addition to the arguments one would expect Ryobi to make—that the saw complied with industry safety standards and that Stollings was responsible for his injury because he failed to use the 3-in-1 safety system—Ryobi framed the case for the jury as a joint venture between Gass and Stollings's attorneys—Mr. Carpinello and Mr. Sullivan—to coerce Ryobi and other saw manufacturers to license and use Gass's automatic braking technology. The district judge referred to this as Ryobi's "conspiracy" theory, though the word conspiracy was not used in the presence of the jury.
Ryobi's attack on the motives of Stollings's counsel began in its opening statement. More than half of it was dedicated to the argument that the case was being brought by Stollings's attorneys to intimidate the saw manufacturers. The implication of the argument was that the jury should not let Stollings's counsel and Gass play them for chumps. Here are some examples from Ryobi's opening statement:
"The evidence is going to establish that there's a joint venture between Mr. Carpinello and Mr. Stephen Gass …, whereby Mr. Carpinello will file product liability lawsuits against manufacturers that don't pay Mr. Gass a royalty for his patent … ."
"Mr. Carpinello has filed over 90 of these product liability lawsuits … and Mr. Gass is his expert witness in every one of those cases … ."
"So what we have here is a patent IP case, an intellectual property case, masquerading as a personal injury case … ."
"There's something going on below the surface and that's why, in [this] opening statement, I want you to be aware of what is going on here. So the joint venture that exists in this case is part of an overall strategy to force the manufacturers to pay Mr. Gass for his technology … ."
"So what are we talking about here? We're talking about an attempt to intimidate manufacturers to pay [Gass] a royalty so they don't have to be sued by Mr. Carpinello all over the country because they're making a saw that complies with what the design standards required."
At the beginning of the opening statement, Stollings's counsel objected, arguing that these insinuations were prejudicial and not based on any evidence. Ryobi responded that it had evidence of the supposed joint venture. The judge permitted Ryobi to continue, informing the jury that opening statements are not evidence. Ryobi's "evidence" was an article about Gass from The Oregonian newspaper. Stollings had made a valid hearsay objection to the article before trial, but the court permitted Ryobi to use the article during its opening statement.
After the court overruled Stollings's objection, Ryobi's counsel continued: "The evidence will establish that there's a joint venture between Mr. Carpinello and Mr. Gass … ." Ryobi's counsel then told the jury about the Oregonian newspaper article and argued that it was evidence of the joint venture. Ryobi's counsel used a blown-up version of the article to draw the jury's attention to what Ryobi believed were the critical points. Pointing to a section of the article that said Gass had been approached by products liability lawyers, Ryobi's counsel said: "Oh, this thing about the joint venture. Gass says he has been approached by lawyers looking to launch product liability suits that ultimately could force companies to license his technology. That's part of his strategy." Ryobi's counsel then concluded: "And that's the case that Mr. Carpinello has filed here, just like Mr. Gass said, to launch product liability suits that will ultimately force companies to license his technology. Part of a game plan to sue the manufacturers all across the country, have Mr. Carpinello coming after the manufacturer alleging to a jury that the product is defective and unreasonably dangerous … ."
Throughout the trial, Ryobi continued to link the motives of Stollings's attorneys with Gass's desire to persuade saw manufacturers to license his technology. Ryobi's counsel made repeated references to the number of saw cases in which Stollings's attorneys were involved, asked witnesses whether the attorneys were involved in other cases in which the witnesses had testified, and read the names of Stollings's attorneys off of deposition transcripts from other cases.
Ryobi also emphasized the joint venture theme in its closing argument. "What's going on in this case?" counsel asked rhetorically: "This is that Oregonian newspaper article. Why is that significant? Because these are quotes from Mr. Gass … and he doesn't deny these quotes." Ignoring the facts that the article did not directly quote Gass and that Gass in fact ...