Ragwing is right. What I want to add is that some helicopters also have what we call "a weak tailrotor". The L3 in the video is a prime example.
It usually happens when the manufacturer puts in a bigger engine and doesn't beef up the tailrotor quite yet. On the next Longranger, the L4 (Lafawnduh), you have a bigger tailrotor and not as many problems anymore.
I am not proud of it but I had LTE once. (Tell you over a beer, G-Man). But I don't believe in hiding my mistakes and usually tell everybody so they can learn from my experience:
Was at 8500 ft when I tried to got straight up and over and obstacle. Was ok in ground effect but when I got into the OGE envelope, we started turning left and went for a ride until I was back in ground effect. Scared the crap out of me but I was able to recover. Same deal, big aircraft, small tailrotor, at max gross weight, hovering right at the edge of what the machine can do, then a slight windshift, ......