Dunno. If someone asked me whether I ever signed lead forms, I wouldn't even know what they were asking. So if I wasn't given the opportunity to ask what this is, hard to say how I'd respond. Were the engineers in the audience given the option to not know, of was this merely a yes/no question?
Maybe it's just me, but could it be that "lead form" is marketing lingo?
I've been to countless conferences or symposiums where people are offered more information on some product or other, if they leave their business card. Hard to believe there's anything odd about this?