I see both sides. I'd say a bum knee would restrict movement to land and avoid strikes. Other side it only went 64Sec if the knee couldnt last that long[ didn't rewatch for any leg kicks to it] Cain should of pulled out.
Cain didn't use it for a excuss than and shows he don't want it for a excuss now. As Maz says "Lets get it on" and see if there's any difference.