It's probably true, considering Jace's behavior, but as always with Jace he could be lying.
That's what I was thinking. You pretty much said it. The thing with Jace is you don't know how
much truth is in one of his statements. Example 1: Jace says. He's a future Marine. When in reality, he probably just applied to join them with no clear answer. 2: If he says " I never miss a target" It could be true, if he was firing point blank with a weapon with little to no recoil.
And this for example, Jace says he got in a knife fight and injured someone to the point of that person needing to go to the hospital.... When in reality, he could have
A: stared the guy down with his knife and the guy pussied off.
B: displayed a tiny blade and the guy could have just left thinking " This clown ain't worth it"
C: An administrator, dean, security guard, or school police officer ( or any combination of said people in authority could have intervened before anything even happened: D: Jace could have lost, only inflicting a few wounds but would glory in the fact that he caused his opponent some injury too ( say something along the lines of tiny shaving or even a paper cut. E: Jace could have been cheap and simply attacked him from behind, and claimed it a " Tactical Victory, before being caught... OR he could have run away after doing the deed and then bragged about it.
The point is, with Jace. his description could be something major when in reality, it wasn't really all that.
But like you say, given his attitude and his mentality. He
could have the potential to do something like that. But I don't know. If what he says is true then it might be because his opponent simply sucked and couldn't fight his way out of a paper bag. Maybe his opponent wasn't all that tough. Eh. Just some food for thought. I think he may be exaggerating his victory if it is true.