It's been told to him, by this point, and not least by Personnel, that he ought not to say 'hey hero' or anything of that sort. Merrin does not like thinking of herself as special or as unusually good at things, and Personnel's best-found-strategy was acting like anything Merrin could do including running eight hours of emergency sims back-to-back was only normal and to be expected.
It's not unusually insane for a non-Keeper, really, just differently insane.
"Good work today," he says.