I don't care what you were yelling about.
Actually, from a purely strategic point of view, it's much better to eliminate the purple one, because Kayle is dead, but Garen is alive, and Chogath already has one armor stack. Watch out you don't get too fat, Cat! Plus, Kassadin might offer assistance later.
What a dilemma! Executing based on a single piece of evidence versus a larger amount of evidence. It's also possible that there's a certain scenario that negates the feasibility of executing based on a single piece of evidence, but we can disregard that.