pineforest,
Verbal bets are binding. Therefore when a player announces an amount and pushes a different amount, they are liable to the spoken amount. You are correct about the dealer. The dealer should have called the bet as 525 and given 500 back to Player A. When a good dealer controls the game and calls the action properly, most of these problems don't exist. The fact that only two players remain in the hand, and the way the dealer handled the incident, I would have no problem allowing that raise. I have to agree with all that you say. The dealer could have easily made things much more clear. Giving change back is okay but, a quick verbal announcement from the dealer should have clarified the bet and then the 1000 and the 25 chips placed into the betting area by the big blind, (especially when he retracted his 200 BB) would have been accepted as a raise.
It would have been nice if the big blind said "raise," wouldn't it? End of problem. Some day, a player might have to announce his raise, but until then, we will have to deal with these situations. The bad news is, we don't always make the right call.
That's how I see it.