Out of all of this, that's your problem?

[Okay maybe she's just a little offended that "you should have died" is the line of question here.]

Anyway, Tamamo didn't have a blade so she couldn't have recreated the wounds Zack had made. So the evidence was never going to line up.

As for why she didn't kill me... probably just another person she could try to throw under the bus if people didn't fall for the idea that Zack did it.