Ive too been in a similar incident. Missed an elbow, as like you was following the play. Turned round to a lot of angry men, one with blood pouring from his head, and not able to do a thing about it. I could have guessed, as i did have a rough idea of who it was, but couldn't be sure. All i could do was explain that i hadn't seen it, and that id be keeping a close eye on thingsalso what could be the possible ways to handle a situation where a player comes to you and says ive been headbutted or elbowed, and youve got car's rather than nar's. i have only had it once and i told him i was following the play your a defender with the attackers behind me. i will keep an eye on them now but please be patient with me if i dont see it