I doubt that's the reason. Back in UNI, a lot of people were farming FBC, and we only had one public IP, so it was like dozens accounts playing all day long. And no one got banned, no one got a a warning, we all withdrew massive amounts of BTC. So yeah, i don't know if i buy the "sister" story. I'm more incline to think it was some sort of referral scheme he was doing
It's probably true. Freebitcoin has always reacted negatively to multi-accounts, especially multi-accounts with the ref system. I honestly don't remember bans for users using VPNs or the same IP address. Typically, in such cases, there was a warning on the freebitcoin site that the IP address was already used by someone.