Obvious call I've never seen a ref make

[Hammerlock3]

I've even asked JR Johnson about this, to which he heartily replied that he would call it every time....until the next time I saw him ref and he did what they always do.

Guy in defending a shot, grabs a foot, tries to rip the guys knee out, dangerous (everything is potentially dangerous) gets called, both guys up. See below, should be timed but 5:28.

How is this not a twisting knee lock? Most high school refs are salivating to hit the top guy for anything vaguely resembling this, but neutral we're all good.