This is referred to as “Schrödinger’s Asshole.” Whether or not a comment is a joke cannot be determined until the reaction the the comment is observed.
If anyone in the DNC wants to deny they said they wrote the emails attributed to them, I will let them do that themselves. It would be a pretty easy thing to do. I take Wasserman Shultz’s resignation as an admission that she really did write the things that were leaked.