well... it certainly fits into the "looks wrong" category.
but.,..
[LAWS]Law 15
A ruck is formed when at least one player from each team are in contact, on their feet and over the ball which is on the ground.[/LAWS]
Well that certainly describes what happened.
The best call is probably dangerous play - but even white's actions are not elbow leading... use fo forearms to push away so "leading with a forearm" .. but they weren't used as anything other than a shoving mechanism.
I'm not trying to justify his actions - just offering an alternative suggestion etc. It could have been just a clumsy ruck creation in a parallel universe.
didds