Was Walker deliberately baiting Cohen, hoping he (or anyone else) would make this kind of Dramatic Gesture, and it would give one of the guards an excuse to shoot him?

Or did she genuinely think, even after everything, that her best option was wiping a chunk of Blake's Contract -- taking them out of the Game, and the whole living world, for the sake of putting them beyond Cohen's reach?

...okay, it's the second one. But "getting Cohen shot" was a nice potential bonus.

After telling her.

[pssshhhh]

Walker: …

[swish]

Cohen: Walker, don’t!!

[BLAM]