Wonderful - proof oncec again that comedy and tragedy are a hairsbreadth apart and if you skate the line skillfully you can go back and forth in a few seconds.
Watch again, and listen carefully to the police radio each time the bobbies are heading out of the door - you always get something like 'Foxtrot Uniform Charlie Kilo ...' just as the door closes. It's so subtle that not everyone heard it, and it is never mentioned - but i picked it up and listened out each time - fabulous!