Police above the law?

Shrewsbury (pronounced as in "Taming of the Shrew" please, not "sh-rose-bury") is a nice historic town here in the Midlands.  One of its inhabitants was out one day taking photographs of some of the attractive buildings.  One of these buildings now happens to be a bank.  A couple of policemen (well, one of them was one of these new-fangled Police Community Support Officers) approached him and - presumably on the basis that they considered taking photographs of a bank somehow suspicious - decided to search him, pushed him to the ground, handcuffed him and took him to a police station where he was held for about seven hours.  The police have now accepted that he did nothing wrong, have offered him a written apology, compensation and agreed to expunge all records of his arrest.  You may well feel that that was the least they could do, but what makes this story worthy of comment?  The fact that it is reported that no action - repeat no action - is being taken against the two officers involved!  What sort of a message does that send out?