Maybe I'm confused. Which law would you presume was violated? Did Django violate the same law when it was named Django? Did Python violate that same law?
The issue is that Tony Iommi is a live person, so using his name can give the impression that he endorses or is in some way associated with the product. Django Reinhardt died in 1953 and thus cannot endorse a product 50 years later. Monty Python is not a person.