The implausible thing there is that if it really was an Iranian mother-drone ship etc, it'd be shot down ages ago. But it's a convenient story for parties that

The implausible thing there is that if it really was an Iranian mother-drone ship etc, it'd be shot down ages ago. But it's a convenient story for parties that want to portray the US as incompetent, even if said parties have tentative alliances / shared interests with Iran.