Outside of Philippe's apartment door, the hall light switch he turns off after Jean-Pierre leaves is not there earlier in the day when Gazala knocks on the door, nor is it there when Sam shows up. It first appears after Sam has left and Philippe is shown looking down the stairs to make sure Sam has left.
Philippe Sainte-Andre (Jonathan Zaccai) is shown in a flashback to 1956 whistling the tune "Colonel Bogey March." While it is true that the "Colonel Bogey March" was originally composed in 1914, it was mainly known in Britain. It wasn't until the movie "The Bridge on the River Kwai" came out in 1957, one year after the flashback that the tune became famous world-wide. Before 1957, few Frenchmen, especially those stationed in Algeria, would have known "The Colonel Bogey March."
In a flashback to 1956 Philippe is torturing a soldier for information about the OAS. The OAS was not founded until 1961.