Without naming names, I understand from friends who favour blue clothing in their working day that an offender who causes injury to a police officer can expect a very interesting ride to the station.
At the very least they may be chained low in the van and given a tour of a city's speed humps :-)
Apparently when the situation is 'explained' to them clearly they seldom lodge complaints.
I'd say that in the example of the scrote in the nicked car, it would be perfectly reasonable for the police rider's colleagues to give the little bastard a kicking on the way to the cells.
And bloody right too.
Jethro and I were in his old shop in Cardiff's city centre when a police van stopped a Ford Escort outside. The passenger came quietly but the driver refused to budge and assaulted the officers who tried to remove him. In short order another Panda pulled up and one of those coppers that South Wales forces specialise in got out (6'2", built like a shithouse). He pulled on a pair of gloves and walked to the car, he peered in from the passenger side, opened the door, stood back and then kicked the driver in the head. After that brief bout of foreplay he lunged into the car and dragged the shouting miscreant out by his hair and collar. Everyone watching clapped :-)
Again, in that case, it was clear to all that the little tw@ had brought such treatment upon himself.
GC