Is a subsonic 308 sufficient for deer, within 150 yds?

Our farm manager took a flatlander to hurt squirrels with him. The guy had never been in the woods much less hunting.
As they were cresting a ridge our subsistence hunter saw a doe across the valley
He shot it about 5 times with his 22lr and said if it's still there when we get back, I will get it.
Well, they got back with a few squirrels and lo and behold, the doe was still on the side of the valley.

Our farm manager mountain man hands the squirrel gun to the non hunter and steps astride the doe with his pocket knife.
The doe proceeds to jump up and bound down the hill. My mountain man drops his knife as he is holding the doe by the ear.
Screaming at the Flatlander to retrieve the knife, finally he does.
My mountain friend dispatches the deer. After having ridden the doe halfway down the mountain, the non hunter says," if deer hunting is this hard, I'm not interested ".

.