It's a difficult grey area. But I wouldn't sue no, either for being told or not being told.
Even the vet can only suggest and advise at the end of the day. Though they could as can anyone, report you for abuse.
Who recalls the thread I started about a welfare person coming over to me and informing me who they were and telling me my horse was fat! They were not working at the time and yes thanks I know as does the vet and I'm dealing with it.
I did take offense in that instance because they purposely poked their nose without taking the time and
talking to me. They talked at me. Big difference Imo.
I'm approachable so to take offense it must have been warranted.