Some questions and details...

First, Spoilers.

Second, most of these have come up in other threads; but since I had the same questions I thought I'd gather them in one thread.

1. I too couldn't figure out whether Jean-Francois recognized his brother when he rowed him out to the submarine. I couldn't tell whether he was thinking to himself (in the voice-over) that they would both talk about this moment and laugh about it; or that he'd enjoy telling his brother the story of how he rowed Le Patron out the the sub.

2. In the scene above, I noticed what might be a mistake. Gerbier tells J-F to take Le Patron out separately and to wait for a light signal of 3 long flashes and a short one. But the actual signal is 3 short flashes and a long one.

3. Near the end of the film, when Gerbier is hiding out by himself, he talks about entertaining himself with the books written by Luc (Le Patron). However, much earlier in the movie, he seems to have a flashback where he 'sees' one of these books in his mind; but it's out of time sequence.

4. Several threads bring up the hat issue. The way I saw it was Gerbier tells Felix he has to wear the hat. But don't we see Felix drop the hat on the train, when he goes on his way to the cafe where he meets Jean-Francois? We see him take off the hat with one hand, while holding the grab-handle with his other. Then he raises his 'hat hand' to smooth his hair and has no hat! In the cafe, he doesn't have the hat either. Later, when he's arrested by the Gestapo, he has a hat on again, which is left in the street. Gerbier too leaves his hat on the box with his suit in London. By the way, at least the Resistance figures got to stay in the Park Lane!

Finally, no one else seemed to mention another good French Resistance film. "Lucie Aubrac." It's not quite 'Army of Shadows,' but very good nonetheless. There's another film 'Boulevard des Hirondelles' based on the same exact true story; but I haven't seen it.

Edit: One other thing. I have another interpretation of the Nazi hats in the cafe where Felix meets J-F. The Resistance fighters are men and women of substance, who wear the hats as disguises. Conversely, the Nazis are empty uniforms. However, they represent daunting numbers and are anonymously menacing But they use the uniforms to give them authority, while not substantive themselves. Empty shirts (hats) in other words.