I didn't understand why he didn't throw a rock sooner but read some instructions on dealing with mountain lions and it said if you can throw a stick or a rock, do it but be very quick picking it up b/c crouching down could make you vulnerable to attack. She was clearly very pissed- the warning "attacks" sent a very clear message.
He also did the right thing by walking backwards and trying to make himself big. I kept thinking, "Where is the guys' car?!"
“Where is the guys’ car?!”
He was in a ten mile run, so it could have been five miles away.