Usyk vs Hunter round 10 clinch Q?

So with about 30 seconds left in the 10th round, Usyk was lighting Hunter up when Hunter tries to clinch. Usyk whips him off hard, and the ref screams at him you can't do that and starts asking Hunter if he's ok. He didn't wrench his shoulder or arm bar him or anything like that? So why did the ref react like he did? I thought it was shitty that a ref reprimanded a fighter for not clinching. Any thoughts/insight? Or did I just miss something?

Who ended up winning?

Usyk pretty much dominated. I didn't see the first few rounds, hunter had some moments in the middle, but the last 4-5 rounds Usyk was in total control

Damn! I'll have to catch replay

Ttt for an answer maybe?

I'm probably in a good position to answer this, I'll have a look and get back.

Just watched it, he basically grabbed the arm like an overlook and threw him and kind of tried to trip him at the same time, not serious but definitely a deliberate foul and refs rightly won't let you get away with that even once. It's well outside the rules for clinching.

*underhook

Funnily enough, you'd probably get away with it all night if you were pressed up against the ropes but you can't make space by moving back if you're on the ropes and it's not potentially dangerous in that scenario.

You can't push/pull/hold but you can use the clinch to make room to work. It would definitely be open to interpretation by the ref. There was no need to Uysk to do it in that instance, he just felt like he had Hunter going a bit and was too aggressive trying to move him off to land some more shots.

He tried tripping him. You can fuck a dudes shoulder up doing that. Pep/Saddler,LaMotta/Cerdan

It's legal in mma as far as I know but Jon Jones fucked up Texiera's shoulder doing something similar

Ahh gotcha. I had a couple drinks in me and didn't review a replay; I didn't catch the underhook/trip, I thought Usyk just turned his upper body really hard and kinda shucked Hunter off with his shoulder. Fair enough. 

I should've clarified that more. Occasionally you'll see a crafty fighter take advantage of a subpar ref and do it-the hooking of the arm and tripping-and the ref call it a knockdown despite it not being legitimate. Recently I can think of Lara vs Yuri Foreman where Foreman went down.

He didn't trip him but the most famous arm wrenching was Mike Tyson vs Francios Botha. He was docked a point and admitted he was trying to break it after the fight. Same thing with Kevin McBride but I don't think he was docked in that instance.