The police are trained to hit a persure point. In pratice this means pinning the person to the ground and if they won't release there hand to be cuffed, hitting them on this spot. More drunk someone is more blows required. Another point is police officers don't normally like to go rolling down stairs and therefore she was proberly fighting with the officer concerned. As most have said, you can't see where he is hitting so jugment reserved. As to how strong someone is when drunk, I have seen when I was a door man a small light bloke pick up a collegue of mine who is larger than me and throw him to the ground, while a police officer was hanging on to his arm. I am 6'5 and my collegue must of been 6'7 and large. I have also seen a women drag 2 police officers along the street as the tried to handcuff her. she was about 5' and light build. These where both down to drink.