rachael's party; my theory *spoilers*
or "did Jon really rape Amy?"
the movie has a very Rashamon-like element to it, in that it shows that the past is subjective to each individual and that your perspective can mold your own idea of the truth. Linklater gives us no concrete answers IMO, but allows us to theorize. so here is my personal idea of what happened the night of rachael's party:
Amy had a huge crush on Jon, and even thought that she "loved him that night," as she said herself during their standoff. Jon, however, was drunk and looking merely for a vessel to satisfying himself (the reason he chose Amy may or may not have been that he wanted to one-up Vincent, because being good friends he probably new that Vincent and her hadn't slept together).
In her mind, Amy had already decided to sleep with Jon that night if he ventured in that direction, but Jon had no knowledge to this. Jon, being drunk and perhaps overly-aggressive, decided he wanted to have sex with Amy. Because Amy thought she loved him, and had already decided to sleep with him, she didn't resist and thought that he just liked it rough. Jon, however, pinned her down and covered her mouth because he EXPECTED her to resist if he didn't.
So, in essence, maybe Jon did rape Amy, but Amy didn't know she was being raped.
Afterwards, because Jon was ashamed he probably didn't make an attempt to talk to Amy again. Amy took this as an indication that Jon had only slept with her to one-up Vincent, his best friend, and maybe that's why she tells Vincent that "there was definately a reason it didn't work out" between them (though some would argue she said this because Jon had got her pregnant). In my opinion, Amy thought she had been used by Jon in a drunk attempt to show his superiority over Vincent, but she was still clueless that in his mind he had raped her.
some might argue that Vincent convinced Jon that the rape happened when it didn't, but if so, then why did BOTH Amy and Jon remember him holding his hand over her mouth? to most people, especially drunk high-schoolers, that is not normally considered consensual sexual behavior.