Tilted camera

there is symbolism i feel.
a straight camera normally means there exists one truth. a singular truth. like in most movies. because they have a resolution. when you finish the movie, no matter how you felt through it, at the end the cards are displayed to you. you know everything.
this is where doubt is special. you dont know the truth even after the end. its a matter of opinion and you will always be in two minds about the truth.
a tilted camera helps suggest that. it splits the frame, but more importantly it literally makes you tilt one way or the other. is he innocent or not?
there is no way in what is shown to us to be conclusive and have a verdict.
that i believe is the symbolism.
interestingly the word doubt, comes from the word dubious, which means to be in two minds.
a person in two minds leans/tilts one way or the other.

It's called the dutch angle. Yes it usually means something, discomfort, character changes, anything the DOP wants to say. (Especially when it's Roger Deakins who does that :) )
In this movie, I recall two occasions, each time there were two following shots in opposite angles (eg, shot tilted left, right after a right tilted shot).
I couldn't made out the meaning of the one in the begining. It showed the people in the church during the first preach.
But the last time it is in the scene between Meryl Streep and PSH. It's when their conversation starts to heat up. Meaning two different point of views are about to clash. And with the opposing angles again, it clearly underlines what they saying at that moment, and emphasize that they're totally on the opposite sides on... basically everything.