I thought this issue (the first one) was dumb. I mean, not only is the self-destruct button such a common word that it might come up in ordinary conversation (albeit, not as likely as many other words, but then how does it know if you're saying Peace or Piece). But then, when the librarian she gets to help her finds the word and knows the killer robot is out there, she starts running and screaming, "I've found the word! I've found it! And I'll tell it to you in just a second, if the killer robot doesn't zap me first. It's..." (zap).
I mean, if that was me, I'd be running out there shouting "PEACE PEACE PEACE PEACE PEACE PEACE PEACE PEACE!"
It was a decent idea to have a threat that Cass can only resolve by reading, and then of course being unable to do so, but the execution was just terrible, IMHO.