I'm in the middle of selling a home in RI now, and we marked "unknown" on most of the lines, because we didn't have the proper documentation to prove what we knew/ were aware of. The previous owner had a bathroom installed in the basement but never got permits for the work, so we couldn't even add that it had that bathroom on our listing.

I would ask your realtor about it, as they are way more privy to what's up with the seller. Could be nothing, but if your gut is saying that's weird, then it probably is.