Symbolism (spoilers)
In the final scene, Maurice, who is dying says "the screen', his final words. These words warn Silien of danger behind his rather lovely Chinese lacquer screen. Silien shoots the screen repeatedly and mortally wounds Kern, the hitman hired by Maurice in prison to kill Silien. Kern stumbles from behind the screen and lies dying on the carpet. Silien turns his back and Kern manages one shot before dying. Silien is now mortally wounded. He calls Fabienne and his final words are "I won't be coming tonight". He looks in the mirror and tidies himself before collapsing, presumably dead. At this point his hat, which he has been wearing throughout, falls off and rolls across the carpet.
At the beginning of the film we are told that 'doulos' is a slang term for hat and also a term shared by police and criminals to mean a police informant. The final shot of Silien's hat falling off his head confirms that Silien is the 'hat', the doulos and informant. Like Kern, Silien was behind a screen throughout the film, waiting to do the dirty and earn a nice living as a result.
I give my respect to those who have earned it; to everyone else, I'm civil.share