
Visible crew/equipment: After Lightfoot steals the Trans Am, when he first encounters Thunderbolt on the run, he swerves into the field, and in a shot from inside the car, a piece of filming equipment on the hood of the car is visible through the windshield. Then Lightfoot hits Dunlop with the car. (00:07:50)
Continuity mistake: In the scene where Thunderbolt and Lightfoot are in the car with the crazy driver. The car goes over the embankment and as it flips you can see a wheel break off. A short time later they both drive off in the same car, with the wheel attached again.
Continuity mistake: When the girl is yelling rape at the motel, she is wearing a bra and panties. After getting some money for a cab, she puts on her dress and she is bra-less.
Revealing mistake: When Clint Eastwood and Jeff Bridges are being chased by George Kennedy and his partner, Bridges is driving off the dirt road down and embankment and you can clearly see that in the passenger seat is a faceless dummy instead of Eastwood or another stunt man.

Visible crew/equipment: At the very end, when Thunderbolt snaps the celebratory cigar in half, in the next shot as the Cadillac pulls away, the reflection of crew is visible on the rear of the car.
Answer: You must be thinking of another movie, because as far as I know there is no different ending.
I totally agree with your answer. Sometimes movies do film alternate endings that may be used in different markets (i.e. Europe or Asia). Also, alternate endings are sometimes filmed after a test audience reacts negatively to the original one and they may show up in the DVD or director's cut. I didn't find any indication that another version was ever filmed for this movie.
raywest ★
I concur - I can't find any evidence of this alternate ending existing beyond some people claiming it does. Like other examples (Wizard of Oz ending with a shot of the shoes under Dorothy's bed, etc.) I suspect this is just a false memory, although no doubt some will argue that, trouble is there's no way to prove a negative.
You are absolutely correct. Just watched this film again for the first time since the 70's. Thunderbolt leaves Lightfoot sitting (respectfully) by the roadside before driving off! Hope you come across this comment one day.