While fighting the rapist, Scotty's hand is bitten hard enough to draw a lot of blood, and towards the end, to be bandaged up. However, in the scene in the squad-room after the fight, his hand is completely undamaged.
Bon Jovi's "Livin' on a Prayer" is playing at the start of the episode, which is dated February 28, 1986. "Livin' on a Prayer" wasn't released until late 1986.