if it was brake issue, I think you are on a good explaination.
If a stone or something got stuck behind the pad, or the pad jammed in the caliper (due to lateral impact for example), you will neither see it in the brake pressure nor in the brake wear sensor (which is normally piston travel afaik), but you would see slightly higher brake temp on this side.
As the brake wears down it will get less and less, until the poblem is gone, which should not take too long - IMHO.
As for the induced yaw, I agree with you that this should be perceptable, but the diff is probably compensating (trying to compensate) for it, so it may does not show up as such.
"Make the suspension adjustable and they will adjust it wrong ......
look what they can do to a carburetor in just a few moments of stupidity with a screwdriver." - Colin Chapman
“Simplicity is the ultimate sophistication.” - Leonardo da Vinci