You're not the only one my friend. My sims are being rolled back with no warning at almost any time.
I watched SweetLeaff roll back twice in 20 minutes to a (the same) previous state. I know it rolled back because a game board containing winners' names and scores was rolled back to two times. Both rollbacks to the same point in time.
Directly after this happening I contacted live help and asked why sims were being rolled back without a request for that. They checked some type of logs they have and said there was nothing in the log recording a roll back. Well log or no log it happened. Many of us sat there in the neigoring sim watching SweetLeaf go down and come back up in the rolled back state. I was asked to contact concierge. I haven't had the time for that
BUT it's continues ... since then Extreme has been rolled back several times. I don't know about Turtle, I don't hang out there that much. I also don't know how many times this has happened when I wasn't there to observe, but I personally have witnessed first hand 4 sim rollbacks on two different sims that were not scheduled requested or warned about. For at least two (the ones I enquired about) LL has no record of it. I can only assume this is the same for the other two I observed. I have had it reported by staff on NUMEROUS occasions but as I've said only witnessed first hand 4 occourances.
I don't know if it's a bug or an exploit, but it's happening. I guess the only thing for now is to be aware and maybe report it every time it happens. For me when it happens there's enough chaos in the aftermath that reporting is the last thing on my mind.
I spent several hours this weekend resetting systems which were totally out of sync because of rollbacks. It is becoming a bit of an annoyance.