Originally Posted by sirdilznik

That part is at least somewhat realistic. Being a big MMA fan I know that moves like the Ankle Lock or a Heel Hook where you twist the foot are mostly just pain maneuvers. That's not to say that you couldn't injure someone with it, but it's not nearly as likely as some other submissions like for example an Armbar (Cross Arm Breaker) or a Knee Bar. With those last 2 submissions where you put the pressure directly against a joint, if you don't get out of it quickly, or tap, you can very easily get your tendons torn or a limb snapped (Angle's "Tap or Snap" motto would apply to these moves much better). With twisting type maneuvers it's usually more a matter of how much pain can you tolerate (I remember a classic MMA fight in Pride between Ken Shamrock and Don Frye where they both had each other in Heel Hooks for seemingly an eternity). It's very rare that you see someone tap quickly to a move like that unless they are new to the ground game and panic.

Again I'm over analyzing.

Edit: Sorry for going off topic so much