Excutor - What am I missing?

Had this a couple of times now… enemy Executor goes first and calls a mass assist, after which the targeted ship (Razor Crest) has target lock, breach and marked. Target lock I understand, they are using their basic, and Marked is because their razor Crest is attacking a breached ship.
However, where the hell is breach coming from??? Am I missing something or is it a bug? Screenshot is without Marked, but I think it still makes the point ;)