This Reddit comment quotes Wikipedia that contends:
After the war, [Karl-Albert] Brüll made a special trip to visit Messiaen, but was sent away and told the composer would not see him.
I'm curious, as I agree with Redditor eddiemon:
He [Brüll] risked his career and potentially even his life to let them go. I have a hard time imagining him as a mostly evil person. Obviously, I've never personally been a victim of the Nazis and I might feel differently if I was, but still, it seems a bit harsh to refuse to meet the man who risked so much for you.
Redditor GoatTnder then contended:
There is more to the story. I'm going from memory here, so forgive any wrong… The guard was turned away from the door by a servant because Messiaen was working that morning and normally wasn't disturbed. When he heard who came to the door, Messiaen tried to follow the guard, but couldn't find him.
So who's correct?
If eddiemon's account is correct, why didn't Messiaen and Brüll reattempt to meet again? Messiaen played the organ at his church weekly; so Brüllcould've found him effortlessly?
An Article in the New Yorker, March 22, 2004 seems to cover why the meeting never took place later(emphasis mine):
Several decades later, Brüll came to Paris and rang at Messiaen's door. For reasons that remain obscure, Messiaen declined to see him. Perhaps he didn't remember who Brüll was; perhaps he was unable to confront this apparition from the past. He eventually tried to correct his mistake, and sent a message to the man who had made his masterpiece possible. But it was too late: Brüll had died, after being run over by a car.