This whole legal vs illegal scrummaging debate is rubbish, and those coaches which are moaning about it know that as well. Every single prop scrummages illegal at some point in the game, if a prop senses an opportunity to destabilise the other prop and make it look like they couldn’t hold their own weight, they will take it. Doesn’t matter who they are.
It’s not just in the bind where this horseplay occurs, but also in the engagement and taking the hit, if front rows can sense an opportunity to make it look like the oppositions are pushing early, they will just pull back on the weight and let them push through. It’s an illegal tactic but if it earns the team a penalty and makes the opposition scrum second guess their own engagement, then why would they stop doing it?
Tupou has been doing no more or less illegal tactics then other props, however he also has a monster engine on him which allows him to do hold his own in the scrum even when the opposition are trying the same illegal tactics on him. That’s the biggest point of difference at the moment, normally illegal tactics can be countered by other illegal tactics, right now, his oppositions are struggling to do so. Hence the whinging..