Nope, didn't know. Just trying to convince Wrex not to freak out, and since it was my first time playing, my charm and intimidate points weren't maxed out. So it ended with Ashley shooting him just as the confrontation was getting intense. Surprised me, then my brother tells me Wrex can survive, which made me want to go back and change the outcome.
Right now I am playing as "Total Douchebag Shepard." If you know what I mean.