Oh my XD
I always wondered why the truck came when it did (maybe it was supplies from Shinra)?. I suppose it was just to add a bit of humour. But then it would have just been boring to have the same old...retreat speech. Like Rufus, Rude/Reno often would after beating them. So in the writer's case "Let's have Palmer get run over by a truck!"
Palmer asked for it he was slapping his arse at the party.
You have a point there about Tiny Bronco though...I'll need to play through it again. I was thinking Palmer started the engine got intterupted and that's when it took off?