Also, signature sheets are certified by the registration of the town or city, so signatures need to be grouped by town or city. Each signature sheet should only have registered voters for that town, because you give the sheet to the town's registrar, and they certify the signatures and cross off anyone who doesn't qualify (including people who don't live there).
That's why the caucus is the best place to get signatures, and town meeting is the second best place: you don't need to worry about what town the person lives in for either, and you just need to confirm what party they're registered with at town meeting.
Do you think he has multiple signature sheets for different towns while he's standing outside the T? Doesn't seem likely.