Just went through this exact thing. The hawk tried to grab my bantam hen, her rooster dove infront of her and he got his head grabbed in the talon, as I was running and screaming the hawk lost its grip and he was rolled through the mud and water and I thought his neck had been broken.  He was just in shock thankfully.  Had a very similar wound on both sides of his head.  First rinse with clorahexadine, then you can spray with veterycine  I then caked original (not the kind with pain relief it is toxic) neosporin over the hole for the first 36 hours, to prevent infection, and then stopped and used only the veterycin as I didn’t want to prolong the healing of the tissue.  One side was actually a bit worse than this, he was in shock so I put him in a dark quiet room in the house without any food, just water so he could get to it when he was ready.  When he started drinking and moving around and come out of shock I added food.  Also put some drench in his water for a boost, and within 72 hours I couldn’t believe how much he had healed.  Just keep the wound clean, and keep their enclosure as clean as possible to prevent infection. With wounds like this I use puppy pads for the floor as they can be changed often and easy. And are clean.  Good luck. I’m so glad you didn’t lose your hen.  Lure some blue jays and crows in with whole peanuts and they will chase them away.  At least they do for me.