IMHO I think that the Police using winches is a bit of a red herring. I have found that Police Officers will not climb a fence over 6 feet or ascend a ladder to look on a roof due to the health and safety legislation in place, not the bobbies lack of commitment but due to supervisors applying the law. Therefore dangling from a winch, connected to a helicopter which is not in SSE conditions would be out of the question.