I see what you're saying, it just isn't very hard for me to take them at their word: They're not claiming that it's Facebook, not out of some sense of propriety

I see what you're saying, it just isn't very hard for me to take them at their word: They're not claiming that it's Facebook, not out of some sense of propriety, but because they don't have any evidence that it is. It could be anyone. And it doesn't matter who it is, because they're leaving for a different reason: Facebook never returns their calls unless it's with an offer of extortion.