The Traitorous Slippery Slope

So how many betrayals are too many? How many times can a friend be revealed as an enemy before someone loses the ability to trust entirely?

I’m debating a very fine little twist that has occured to me. If I follow it, one character dies. If I don’t, a different character dies. Both are good guys, both are characters I have a big personal investment in. But one death would come from the betrayal of a friend, and the other from rescuing the same friend. The only thing that would change would be the true loyalty of the first character.

And I don’t know which way to go, or which would serve HAWKSPAR better.