Someone at the keysigning party later said: "I didn't get a signed key from you yet.. I'm not signing your key until you sign mine, because I've been burnt before". LOL. Tempting to reply & say "who's to say I can trust you to follow through? Maybe we should meet again and do an in-person exchange of signatures with impartial witnesses present."
I suppose we could expand the process, so everyone sends the signed keys to a trusted intermediary, who then witholds sigs that would go to someone who didn't do their homework.