What possible reason could one have to accuse someone of stealing a third person’s art without proof?

The troll wants to get the artist banned out of jealousy/spite, hoping the mod takes the bait. Their blog makes their motivations more obvious but the troll is pretending to be a civil “concerned citizen” here particularly on the bright red account.

Sidenote: how is this “off-site drama”?

I think the mod just saw how the links were to places like YouTube and other sites and assumed it must be off site drama without realizing Red is a troll.