What kind of lighting was it under in the other tank? What kind of lighting do you have?
And fwiw, it looks like there is some polyp extension in the pics, which is a great sign for the chances of recovery.
+1 to everything said above. Do you have other sps in the tank or is this your first?
Next time i might not RX dip since i have melanurus wrasse already.
Risk / Reward for RX dip just doesnt justify me.