Keep in mind anyone can put data on the spreadsheet if they don't post on the forum is hard to prove who is the owner of the account.
You need to open the profile link on the forum search on their post history and see if they are really the owners or if someone is hijacking their accounts.
i have once caught cheaters who tried filling my details on the spreadsheet while i don't participate on that same project, where the person was actually caught was proof of authentication as he uses another's man post to fill out the form. so if that there was no proper information i would have been penalized for what i don't partake of, so we have to be very careful summarizing any information on google sheet and if that must be the POA has prove the person right or anyone without such post won't be proven right.