It's real, I just had a Telegram conversation with him which I can provide here on request.
While I would say it was a very foolish idea for him to give a spammer access to his account to participate in a sig campaign on his behalf (he could've just sent the campaign money to his address for example), it technically was not his own plagiarism.
Not to doubt you at all but just for a moment if we accept it was an innocent mistake, should there be zero sanction?
Obviously I do believe that there should be some form of punishment, but I don't have other details about the situation, particularly:
Did the OP ask the Stake manager if he would be allowed permission for someone else to post on his behalf? Did the OP ask the Stake manager to change his payment address until the foreseeable future? If this was an innocent mistake, he created the problem simply by allowing someone else to access his account when it was not necessary and that person abused that trust therefore he (not the other party) are now facing the consequences.