I do not believe in Evolution . . . but if I did I would say this looks like a prime example of evolution weeding out the weak. Stupid is as stupid does.
OMG, even at 10 minutes into the video these people still don't exhibit any urgency to get to higher ground. Stopping and still taking pictures while standing in the ever rising stream is just unbelievable. I am thinking you have never seen a flash flood and how quickly water rises, carrying logs and boulders, but geesh, you were witnessing it first hand and were still not staying out of the stream, booking it to higher ground. Heartbreaking to watch the camera person just crossing the stream repeatedly, never looking back to make sure his two companions are okay.
This looks absolutely terrifying. Did you check the forcast? I noticed that you had no backpack or gear with you. At the very least a rain jacket could have helped to keep your upper body dry and also provide some protection from hail. It doesnt matter how small the walk is. Ive been on that trail. Always carry a pack with proper gear for the terrain. Im glad you made it out safely.