Quote Originally Posted by brad View Post
sounds normal to me.
Yep, perfectly normal. The car is detecting that you want to maintain or reduce speed going down hill (because you are applying the brakes), so it is downshifting to a lower gear to improve engine braking.

I've found that a couple of times I've caught the gearbox offguard when I've released the brakes just as it is starting the downshift revmatch process, and I see the revs increase before dropping back down again.