Especially this. Even worse: they might hear that functional programming is the new trendy thing, and for loops are passe. That you should always bury your control flow in a lot of small callback functions without the appropriate amounts of equational reasoning that must go with it, killing your ability to really debug your programmer. Or they might hear about TDD, and apply it in a very wrong way because they really don't get development very well. Actually, the only thing worse than a non-coding manager is a manager who tries to "keep up" without really being in the game.

A good dev manager is able to see the good over the fad.