Word for a misdirected exaggeration?

This morning I was typing some vb code with a coworker looking on, and we were discussing the run time for the module. He suggested trying to speed up one section by adding a loop that would, as he put it, “take like, three seconds.” The comment was meant to imply that it would then take a negligible amount of time for that section of code to run. The problem is, by implementing his suggestion, it would then literally take a negligible amount of time, so his exaggeration worked in the opposite direction since three seconds is an eternity when compared to virtually no seconds. Is there a word for this sort of misplaced exaggerating?