Fëanor fails to register that he's not helping so he continues as if nothing happened.

"There are a few up there for sure. I've heard howls so they're not far." He shrugs. "If you keep close to the shepherds you'll be fine. They have dogs, they're used to dealing with predators but they'd be grateful for all the help with the herds."

Is he absolutely certain of this advice? Nope. Look, he's elvish royalty. He'd never had to deal with a single goat or cow in his life. They're filthy, smelly and try to chew at your clothing if you're not careful. He's not happy about this situation either.