They were paying people to collect them. If they were just doing it this week and when the guy came in he hadn’t asked for the addresses, then they were stuck with submitting these. I can imagine a lot of people might be willing to sign but would not be willing to put their address down. It just doesn’t stand to reason that the campaign would have had enough time this week to eliminate those suspect ones before turning in the 11,000 they did, which means it’s unlikely 90% of what they turned in was valid.
Or EXTREME incompetence.