I'm 100% certain I know the answer to this, but I said I'd ask the experts.
There's a monster in WotR that makes you roll a d20 and compare it to your 'hand size'. My interpretation is that this refers to the maximum hand size as printed on the character card (plus any hand-increasing power feats). The other player interpreted it to mean 'however many cards he has in hand at the time'.
So, of course, with a max hand size of six, but three cards in hand, he rolls a six. Should he have suffered the effects of the monster, or not?