Well, we don't know if it's just the personality - is it the same Megan who resurrects? And just because "she's always resurrected before", doesn't mean she definitely will the next time.
And I'm going to guess that being shot is a pretty unpleasant experience, let alone the experience of dying.
I find myself feeling "Yeah, it's not a 'fair' fight, and it would be nice to avoid killing in those circumstances. But I think you'd need to be pretty saintly to let someone shoot you instead."