just read your post about Dumbledore where you mentioned him not knowing about the potters' actual secret keeper. I do suspect, based on nothing, he did know or found out and then let an innocent man go to Azkaban so Harry will stay with the Dursleys because obviously Sirius wouldn't approve of their treatment of him and Harry wouldn't stay with them if he thought he could go live with his cool uncle. How probable do you think it is?
Doylist answer: nah, that isn't the read intended by the books.
Watsonian answer: you could write a 100% canon compliant fic where that was the case, and I would read it. I think there's a case to be made that Dumbledore just doesn't trust Sirius because Sirius (beautiful, brilliant, dark magic background) reminds him of Grindelwald. I think you can say the same thing about why he has such a knee-jerk aversion to Tom Riddle
Personally, I love making Dumbledore smart but shady in fics. I spitballed out Dumbledore's very lax protections of werewolf!Remus while he was at school into something he did on purpose, and had a ton of fun folding that characterization into Prison of the Phoenix.












