This is something the helper mod should have disclosed, especially if they would be interacting with players in a mod role.

Sounds suspicious to me and looks like they might be looking for ways to get around the opt outs or to make life uncomfortable for those who have. First priority is to immediately remove as mod without a doubt, ban at your discretion but I would do so myself. no point in risking it and they have already proved themselves to be untrustworthy.