I am not an expert. I'd only say that i learnt from cichlid-forum.com - the hiding might be first sign of disease such as malawi bloat.
You need to watch closely for their appetite and poop (white stringy one is no good).
Stress after WC passes fairly quick, i do not think tht they can keep painful memory for a long time, they usually forget about everything after very first meal.
My JD, after his occasional freak-out (sometimes i do not even know what caused it), can go sulking for long 15 minutes but his curiosity and hunger usually drive him out very quickly.