They shouldn't under any circumstances whatsoever ? What if the suspect had a weapon ? Had a hold of you and was trying to bite you ? I accept that wasn't the case here but cops can punch someone in the face as can anyone but the circumstances must warrant it and you have to be able to justify it.
What? Biting? So the outcome of punching him the face was...?? Knocking out his teeth so he can't do it again?
I respect you as a police office - but saying that officers are allowed punch people in the head to stop them from resisting arrest (or biting) is a bit over the top!
Whilst your at it, why not get your kosh out and smack him in the head with that if punching doesn't work!
Is punching someone's head when they are close to concrete floor not a bit risky?
Hopefully common sense would prevail here a little more often?