When Cordy is bandaging Angel she puts a strip of tape on the bandage running up and down on her right side, Angel's left. The next time we see Angel shirtless he is getting into bed and the tape is gone from the bandage.
When Bethany returns to Layla's place after her attack in the alley, there's no blood on her forehead (which is OK, since she probably cleaned it up) and there's no visible wound, cut or swelling, either.