I agree with Kevin. Between the stress of transport, new tank placement/acclimation, and falling into the other coral - it has likely stressed the coral to the point of succumbing to a fatal brown jelly infection.
What I would do is this. Remove the frag
from the tank to a small bowl of tank water. Gently shake the coral in the bowl of tank water until all of the jelly/slime is removed. Is there any coral tissue (orange coloration) remaining? If yes, it has a chance, if totally bleached - it's a goner.
If it has some tissue remaining, I would attempt a Tech-D dip (Kent product). I would then place it securely in the tank in a moderate current. Don't try to place it where there is no current - it needs decent waterflow to wash potential "slime" and algae off of it's tissue.