Trying to save his butt, chickens are prey, they escape. If you were expecting him to stay and fight off the hawk, it is not going to happen.
A rooster's job is to be aware. He should be the first to notice you, when you come. Hens are always head down, looking at the ground right in front of them, easy to sneak up on. A rooster, will do that too, but he bobs up more often, and seems to look farther afield when he does. He will sound the alarm, and everyone will scatter.
I have coyotes, hawks, owls, and coons. A year old rooster is big enough, and mature enough, to really start making it hard for a predator to sneak up on the girls. Once I have a good rooster at that age, my day time predation drops.
However, nothing is good against coyotes, or coons in the night. They are just too much bigger. I have had a rooster take the attack, and be killed, but all his hens escaped. And I have had a rooster loose all his tail feathers (I thought a bobcat). But these were all mature roosters.
Not all roosters are good roosters, in fact I would go so far to say, a lot of roosters are not good roosters. But they do need to be at least a year old, younger than that, and they are just into chasing tail, not the other responsibilities.
Mrs K