I don’t see any rule that would make this illegal. Even the tumbling section says that side rolls aren’t tumbling, so it wouldn’t be tumbling over anyone. It’s close to being inverted, but not close enough that I would call. If the base leans over enough, the top could end up inverted, in which case it would be illegal by 3-3-6.
But as performed, it’s legal. There’s not a rule to cite, because it’s just legal by all of the non-release stunt section rules. Make sure they do not become inverted.