Actually to be fair to the police, they were called out, presumably by the crew, and so had to follow procedure which includes taking statements. We cannot expect the Police to attend and not follow up statements etc etc. Ok, it was only a smoker but that leads me to my next question. Was it really necassary to call the police? As crew i find it much more effective to explain why we don't allow smoking (especially in the toilets) and that I would be informing the captain. That normally does the trick unless something else happened on your flight.
So in actual fact, you could say the crew weren't the best at dealing with the situation and that the Police were only really doing their job.