When Ezra puts exile on Commander Ahsoka (CAT) - it should only stop CAT from assisting. It also stops Snips from assisting as well, Tested in arena battle with my JMK team without Ezra vs a JMK t...
Ideas
The first time Ezra is Exiled, enemies can't assist or attack again if their attack is targeting Ezra.
Chances are you were targeting ezra while using specials and snips couldn't assist because his of unique not because of the exile itself.