Mizzi reaches the counter and begins remonstrating with the officer at the other side of the counter's glass partition. The visitor's temper flares, so the officer dealing with him dons a stab-proof vest.
Mizzi walks three or four steps towards the door then spins and whips an imitation shotgun from under his clothing. As Berkett opens the door to step into the foyer, Mizzi steps forward and points the replica at him. The constable scrambles backwards and falls in fright.
For all intents and purposes (and because the film was silent) it looked like he had in fact been shot, so quickly did he hit the deck. So traumatised was the constable and father, he later resigned due to the consequent flashbacks.
One can only imagine it also ruined his Christmas Day.
Like all memorable films, it elicited pathos from the audience. And so it should.
The CCTV footage was a reminder of the dangers (real or imagined) the constabulary puts itself in while the rest of us sleep soundly on a Christmas morning.
All the best, Mr Berkett. Here's hoping your silly season this year is nowhere near as silly as the last.