Yes............. That's what is the doctrine of unclean hands.
The plaintiff can suppress material facts favourable to him, without anybody' compulsion !! (at his own risk...but as a legitimate expectation nobody commts suicide for fun!)
The plaintiff CAN NOT and is NOT supposed suppress any material fact which is deemed unfavourable to his claim, knowingly. (but again ........... if plaintiff can't supress those facts then he shouldn't climb the steps of judiciary to claim any relief ............ which he doesn't deserve on merits!!!)
And hence ................ if occurance of 'unclean hands' expose takes place in a trial .... then other party has the right to demand the reversal of previous judgment, or dismissal of suit if trial is not disposed.