Your lab would be dead meat. Once they know your dog's territory, the coyotes will send out a fast yearling to bait the dog into a chase, right back to the hiding pack. One will turn the dog, while another takes out the Achilles tendons. Then it's all over for the dog.
I almost lost one that way but she figured it out and split before they got her.
She did this for years and they were terrified of her. 70 pounds of lab coming at you in the dark forest at full speed would readjust your attitude right quick.
I have seen her take off after them and from the sound of the coyotes screaming they cannot see her in the dark and she seems to knock them over or possibly knock them into the air. Never heard that sound from a canine before. She comes back with spittle on her head and a smile on her face.