I don't even think he'll be banned for spamming: posting the same thing after you deleted it could be considered a bump.
A bump? It might technically be considered that (even if it's stretching the definition), but it's not a bump in spirit and I think we all probably can agree on that.
We can agree, but the point was I don't think they'll be banned for this. Even if it's spam, it's gone already. Even plagiarism won't get you banned if you delete it by yourself.