Not according to two people with access to voting files in Ohio, says Ben Smith. Pardon my skepticism. First of all, the fact that they were actually checking his registration to vote tells us that they’re not likely McCain supporters. They were looking to discredit Joe’s opinion. Even Smith writes:

And yes, the freelance opposition research on Joe began before the debate ended.

Second of all, Ohio is the state whose Democratic Secretary of State tried to allow people whose applications were mismatched with their actual information to vote. I think it’s possibly that two unnamed people with Ohio voter file access could be, uh, deceptive to help a Democrat.