I've had it happen before myself . General was on a hill well above and a good distance from the actual fighting when it happened .
It sounds like one of those bugs that we'll be told is in our imagination .
It's probably happened to others whom simply assumed the unit took a hit or some such so didn't realise .
I do hope it isn't some cheesy "well sometimes people panic for no reason" "feature" that they forgot to mention .

Mabey the moral calculations might in vary rare instances forget to drop penalties for the generals' unit that have stopped being valid or might perhaps be dumping those of several other units on the general ? I'm gust wildly guessing though .