From The Shambhala Guide to Aikido by John Stevens; page 28:
"There is an interesting story regarding the noncompetitive, defensive nature of Aikido. After the war, Morihei refused to let any matches to be held in the Hombu Dojo, but once, for some reason, he relented and let Koichi Tohei, one of his top disciples, square off against a professional wrestler from South America. Usually such challengers rush right in and attack, but the wrestler held back. After some minutes of stalemate, the impatient Tohei moved in and forced the issue, managing to get the wrestler down and pin him. Morihei, however, was quite displeased: ‘There is no need to throw someone who is not attacking you!' It seems that the wrestler had first visited the Kodokan Judo headquarters. There he was advised by the Judo people, ‘Don't attack an Aikido man first; if you do, he will be sure to throw you.'"