I'm pretty sure he has a leash, or two.
Sometimes they just get away from you.
Add in shotguns, snow,sleet ice,deep thick cover, then add a pushed deer or two, and you really have to be on your toes.
Peanut was just following her instincts. Truth be told, she may have worked it out all on her own, but there was no need to risk it.
They can get away so quickly.