You keep on making it about the fact that she slept with dudes. That's not the issue. The issue is that she lied. If any part of the Jury decision requires that they view her as credible and truthful, the lie hurts that.
It's weird that anyone would doubt this given how many scumbag dudes have gotten out of trouble by simply proving that their accuser was a liar and loose.
This does hold some truth to it depending on who is on that jury. But ultimately the disconnect in this is because who she fucked has no bearing on the ultimate question of who shot her. It may explain why the altercation began but it still has nothing to do with whether or not one of those two people shot her. And some will use that logic to try and explain away the responsibility of the people with the gun residue on their hands