When in the wilderness - make sure to make noise as you hike so the animals know you're coming - do not quietly run along it like this fellow. If with a hiking partner - talk loudly - even if it's nonsense. If alone talk loudly to yourself - even if it's non sense. If you do come upon an animal - rattlesnake, moose, grizzly bear, cougar, mountain goat etc. -STAY AWAY ! (I've encountered all of these at one time or another on hiking trips).
Do not approach trying to get pictures or to tease the animal. The animals do not want anything to do with you and will go away if they hear you coming up the trail. You are in trouble if you surprise them (especially those animals protecting their young) or try to get too close or tease them. This fellow should have considered playing dead. The cougar might have lost interest and stopped following him.