He will be ok. He's scratched his own face and it looked far worse than this did, but it was self-inflicted and not because he got sassy with a hyacinth. Someone had already broken them up by the time we got back there. The hyacinth really loves the guy who works back there and he easily stepped up for him when asked. That's the same hyacinth that gave me a pinch when he wanted his favorite human and I didn't hand him over fast enough. The blue & gold is a silly boy on his own. He will step up just fine, but once he gets on the floor all bets are off. He won't step up for anything, but it's all part of a game he plays. What I've resorted to doing is picking him up like a chicken. I grab him right around the middle of the body and lift him up. He starts to laugh and say HI! while waving his feet.
As for breaking up fights between big birds - at home, I keep a small throw pillow handy. If they start to snap at each other I toss it in their direction. It's not big enough to hurt if it hits one of them, but enough to interrupt the behavior. Usually seeing something flying toward them is enough to send them scattering in different directions. At the store we keep them separate on hanging trees, but sometimes it takes just a second for one of them to get down and start something. When I was cleaning I kept a hand towel in my back pocket. Waving it at an aggressive bird will distract them and keep them from biting you.
A few weeks ago as we were about to lock up and leave there was this horrible screaming in the back boarding room. The owner went back there and found Sandy on top of another bird's cage carrying on. She stays in a different room and doesn't go back there with the boarders. When we went to put her back in her cage we discovered it was locked. The only thing we can figure out is that when I was doing a walk-through I pointed out that she needed more food in one of her dishes and someone left the side door open when they took the dish to refill it. She slipped out and got down on the floor when no one was looking and the person who put it back didn't notice that she was gone. She doesn't fly so she waddled her old bones across the store and climbed up onto the cage and started carrying on. If she had gone somewhere else we might not have noticed she was gone because the cage check had already been done. I don't want to imagine what kind of bad things could have happened. At the very least, she would have set one of the motion sensors off and the alarm would have sounded, but she could have climbed up the hyacinth cage and that might have been deadly.
I get a chuckle every time someone comes in and says they would love to get paid to play with birds. It's nothing as they imagine. We really do run it like a daycare where we have to keep watch over children to make sure they stay safe and happy.