Was my chip burnt ?

The Absolute maximum rating on that is 1.8 V, so since it was stressed, that answer is probably yes.

Usually it will fail as a short to ground, however, since you were only pulling 190 mA, you have some chance that the chip survived.

Have you identified what caused the supply to go to 2.5 V? Was it an issue with the feedback circuit or does it only happen when loaded.

Since you were able to pull isolate the 1.2 supply, try looking on the other side with the supply up, and see if you a short to a 2.5 V supply.

If you a have another board that wasn't powered up, that exhibits the same problem, it's probably a short in on the board.

Pete