my cards get mucked, standard?

[Merton0806]

i was dealing (and playing) at a poker tourney yesterday when 2 players went to the flop and i was gathering all folded hands. i accidently collected one active players cards and he pointed this out to me. i decided the best course of action was for him to whisper me his cards ( he is good player therefore can remember the suit(s) ) and he whispered AdQd ( which bore no relevence to the flop)and in the pile of folded cards AdQd were next to eachother. so i gave him them. everyone seemed happy with the way it was handled but i wasnt sure if it was the "correct" way. ruling plz?