I actually don't, so this was a really enlightening post. It does sound like the "correct approach" depends on understanding the training of both the dog and the handler. I'm going mainly off of first-hand experience with aggressive medium-size dogs of various breeds, and the introduction of the dog/handler dynamic is a critical difference compared to a dog by itself.
My armchair theory is based on the assumption that these handlers will be a bit reckless, lacking experience and probably a bit low on the morale side. That might not be the case. I simply don't know enough about the ins and outs of police culture in the UK.