Car chases

I have just watched a back episode of a programme about the emergency services. One of the incidents included a man who gave chase to a car containing some lads who had just tried to steal his son's moped. The following driver continually broke traffic rules: speeding, driving through red lights etc. When he rang the emergency services they just accepted that he had given chase. I was staggered that they did not immediately tell him not to give chase and that he would be at risk of legal proceedings if he did not stop. After a long time, the police did eventually tell the man to stop giving chase - they were communicating with him via his mobile phone - in other words yet another offence!

The car in front finished up turning over and at one point both vehicles were doing 100 mph. The man driving the following van was not prosecuted for dangerous driving - I wonder why not?

I have seen programmes like this where the police themselves seem unwise in their decision to chase another vehicle - the person being chased feels forced into driving dangerously and the police themselves will be driving too fast. There seems to be no balance between the dangers of giving chase and the offence that has been committed. Is it worth risking innocent people's lives for?

I speak as someone who was forced of the road in a blind bend by a fire engine going so fast that it drive on my side of the road.