Berger and Bukowski trading places
I loved this movie as a teenager, and in many ways, I still do, but though as a kid, I could suspend my disbelief enough to buy that Berger winds up on the transport plane, in Vietnam, and then getting killed there, as an adult, I just can't get there!
There are just TOO many things that would have to go wrong for that to happen. One of his bunkmates would have recognized that it wasn't Bukowski, someone there for sure would have realized it, he himself would never have got on the transport, he'd have screamed "I'm not Bukowski!" and refused to go and damn the consequences. I mean, really, after all the illegal and crazy things he's done throughout the movie, he would worry about getting in trouble for pretending to be Bukowski (or worry about getting Bukowski in trouble for going AWOL?) No way!
If somehow none of the other soldiers recognized him AND he got on the transport, I'm sure it didn't go straight to Vietnam, it likely stopped in Hawaii or Japan or somewhere and THEN the truth would have come out. Or if it did go straight to Vietnam, there'd have been some sort of check in process where the truth would have come out.
It's simply unbelievable that at NO point did he ever say "uh, hey, I'm not the right guy" and the proceed to give the story of why he traded places and take the consequences. Even if the officers didn't believe him, they'd detain him and check out his story, not just send him out to battle.
I just can't suspend disbelief enough to accept this ludicrous scenario.
Other than that, I still very much enjoyed watching this again.