APPEAL from the Circuit Court of Cook County; the Hon. JOHN J.
MORAN, Judge, presiding.
MR. PRESIDING JUSTICE SULLIVAN DELIVERED THE OPINION OF THE COURT:
Judgment was entered on a jury verdict in favor of defendant in an action to recover damages for wrongful death and personal injuries arising from a single car accident. On appeal, plaintiffs present questions as to whether the trial court erred in (1) directing a verdict for defendant on their res ipsa loquitur count; (2) ruling on certain defense expert testimony and exhibits; (3) allowing a defense expert witness to be present as defendant's representative at trial; and (4) giving certain jury instructions.
Plaintiff Vincent Bigelis (hereinafter Bigelis) testified that he and his deceased wife (hereafter decedent) purchased a new 1973 Pontiac Ventura automobile from Hoffman Pontiac *fn1 on May 31, 1973. On the morning of July 21, 1973, Bigelis and decedent left in the Ventura for a vacation in Canada. They traveled without difficulty via Interstate 94 about 85 miles to their farm in Michigan, where they stopped briefly. When they resumed, decedent was driving. The weather was good and the pavement dry as she entered Interstate 94 (which was three lanes in both directions) and proceeded east in the right-hand lane at a speed of 60-65 m.p.h. She had driven approximately 10 miles when the accident occurred, concerning which Bigelis could only recall that the car collided with the guardrail on the right side of the road and became airborn and that its hood appeared close in front of him.
Charles Aarup and Debra Kortum witnessed the occurrence. The former testified that he and Kortum were in a vehicle traveling east on Interstate 94 at 60-65 m.p.h.; that after passing a car, he looked into his side mirror and saw the Bigelis car approaching in the far left lane at approximately 80 m.p.h; that Bigelis' car passed the car which Aarup had just gone by, and the Bigelis car then veered sharply off the road to the right behind Aarup's vehicle — striking the guardrail and flying into the air. Kortum testified that she saw the Bigelis car swerve "as if it had made a complete right turn" and then go over the guardrail.
It further appears that after jumping the guardrail, the Bigelis car landed on its roof and tumbled down an embankment before righting itself and coming to rest more than 100 feet from the highway. As a result of the accident, the hood was torn off and most of the engine parts were damaged. In particular, the top half of the carburetor (including the fuel bowl) was sheared off by the impact and was found in the right corner of the engine compartment, where the battery is ordinarily located. The base of the carburetor (a cast iron assembly called the throttle body) was still bolted in place, although one mounting bolt was broken. The throttle plates (two circular pieces of metal which govern the flow of the fuel mixture into the carburetor barrels) were undamaged.
At trial, plaintiffs' theory of the accident was that the throttle body extension (which contacts the tab on the throttle lever and is a component of the throttle body casting in the carburetor) was cracked and eventually broke off, causing the throttle mechanism to be jammed in the open position. In support of that theory, plaintiff presented the testimony of six expert witnesses.
William Rudd, a service station manager experienced in mechanics, testified that three weeks after the accident he examined the car and took photographs of the engine compartment, which showed the carburetor throttle plates to be in the horizontal or "closed throttle" position; that he subsequently removed all the carburetor parts and examined them in a laboratory; that the throttle bracket or lever (a metal piece connecting the throttle wire and the accelerator pedal to the throttle shaft) was completely bent over the end of the throttle body at the base of the carburetor by the impact; that when he bent the bracket back, he found broken fragments from the throttle body extension; that although he had no metallurgical expertise, it was his opinion that there had been a crack in the throttle body extension prior to the accident based on rust deposits he found on the broken fragments by examining them some 56 days after the accident, during which time the car had been outside; that nothing was wrong with the car's suspension, steering, or braking systems; that tire marks at the scene on the highway had been made by the right side tires accelerating and braking; and that black residue on the brake drum indicated braking prior to impact.
The evidence deposition of Allen Cheung, a chemist with a metal testing company, indicated that he made three chemical analyses on pieces of the throttle body to determine the percentage contents of various elements; that he obtained different results from those tests, but the differences were allowable under the procedures used for cast iron testing.
Darryl Albright, a metallurgist, testified that the throttle body met all hardness specifications; that the thickness of one wall of the throttle body extension was insufficient and reduced the strength of the casting; that the manganese, sulfur, and silicon contents of the broken fragments varied slightly from defendant's specifications, but he could not say with scientific certainty and in the absence of testing specific samples that an increase in the sulfur content alone would affect the strength of any throttle body casting; that on the basis of his tests, the casting in question met defendant's hardness specifications; that there was a prior crack in the throttle body extension; that while he thought the throttle was open (despite the absence of physical or metallurgical evidence to that effect) at the time of the accident, he could not explain why the throttle plates were undamaged since, if the throttle had been open, the throttle plates would have been in a vertical position sticking up into the fuel bowl assembly — which was sheared off by the impact; that it would have been helpful to the formation of his opinion to have seen the undamaged throttle plates and the bent throttle bracket; and that even if there had been a crack in the throttle body extension, it would not have affected the normal operation of the carburetor.
Jack Campau, a consulting engineer, testified that in his opinion a piece of the throttle body extension had broken off and lodged under the throttle lever, thereby jamming open the throttle shaft and throttle plates and causing the driver to lose control while applying the brakes; that although the brakes on the Bigelis auto were fully functional, they would be unable to stop a car with the throttle open; that in his examination, he determined that decedent had applied the brakes at the time of the accident, although in his discovery deposition he testified that he had seen no physical evidence of an application of brakes; and that decedent had taken "improper action" to correct the problem caused by the purported jamming of the throttle mechanism.
Thad Aycock, an accident reconstruction expert, testified that photographs of tire marks at the scene showed they had been made by left side tires; that he found no evidence of wheel lock to indicate that the brakes had been applied; and that the driver's steering of the car was the cause of the right turn and its catapulting over the guardrail as it did.
Stanley Sedivy, a mechanical engineer employed by a consulting engineer firm, testified that the throttle plates could not have been in a completely open position at the time of the accident; that they could have been open 35 to 40 degrees due to the action of the driver and thereby avoided damage on impact; that he found no evidence to indicate that the throttle plates were jammed open prior to the accident; and that the impact caused the crack in the throttle body casting.
Defendant presented the testimony of five experts. Ray Schultz and Cletus Becker, engineers in its employ, testified that they tested the throttle body casting for hardness and chemical content and found that it met defendant's specifications except for negligible variations in the manganese and sulfur contents that would not have significantly affected its strength.
Edward Holmes, a safety engineer with an independent consulting firm, testified for defendant that none of the thickness measurements or chemical analyses in evidence affected the strength of the throttle body casting; that the direction of the bend in the throttle shaft and the undamaged condition of the throttle plates indicated that the plates were closed at the time of impact; that if the plates had been open, they would have been damaged when the carburetor assembly was sheared off; and ...