What's it called when you have a discussion and they just quit the argument because they can't back up what they're saying. Yeah yeah, the colloquialism is rage-quitting, but that's not what I'm talking about.

Feminist: Blah blah blah.
MRA: Prove it.
Feminist: :withdraws from the argument in a way that they try to save face so it doesn't seem like they're not able to defend their point, possibly using snark or sarcasm: