I currently have two Rabbitfish (different tanks). I've had these kinds of fishes for as long as I've been in this hobby. From my experience with them, I am about to make what might sound like a stupid statement --- Rabbitfish seem to
know they have a good defense mechanism and don't hesitate at all to use it.
I will observe my Rabbitfish over the years extend its spines at the slightest provocation and sometimes even where there is no provocation at all, but maybe just another fish got a bit close. They are a shy fish and easily threatened.
Angelfish can be shy too, but they have a way about them to go about nipping at things. I always thought it was their way of finding possible foods to eat. Over the years I've seen my angelfish occasionally nip at the dorsal fin of another fish. It doesn't seem to be aggressive, more like testing!
If you put those two fishes together you have the potential for what you suspect -- the angel ran into the Rabbitfish.
Under these circumstances, I'd wait. Have your QT up and waiting though. Watch for any signs of it worsening or spreading and any other signs of poisoning.
If you want to give the tank a boost and maybe a little bit of insurance, do a large water change today and tomorrow.:rollface:
