I'm guessing it was because you're late. My Golden Comets are idiots and don't notice when there is a predator around- they walk up to the fence when my dog is on the other side then act surprised when the dog tries to get at them. On the flipside, our rooster (Maran/Langshan) gets freaked out over squirrels.
My hens cluck & make all kinds of racket when I go down to let them out- usually between 7:30-8- the past couple of days with the holiday, I've been kinda lazy and it's been later and they haven't been any louder. It's funny though, the earlier I go down there and let them out, the more likely I am to get attacked by the rooster. I guess he's just not a morning bird.