Delivery man in Japan treats his packages badly by smashing them into the ground

On Dec 6th, a shocking video was upoloaded to YouTube.
In this movie, a Sagawa Express delivery man seems to be irritated and keep on throwing, slapping onto ground or other packages.
In the end this movie ends when delivery man fade out of screen, picking all packages up and load on to hand cart.

Sagawa Express is pretty famous and one of the biggest delivery companies in Japan.

For answer to BuzzFeed's question, Sagawa Express's PR person answered as follows.
"He is surely our employee. It happened in the middle of delivery"

The delivery in the video explained "I did it for selfish reason. I was irritated in many ways. IO regret it".

Sagawa Express is trying to find out which specific packages were treated in wrong ways.
It seems packages itself were delivered properly.

BuzzFeed also questioned that possiblity of overwork, since he is obviously irritated.
Sagawa Express denied it saying, "We do not make him overwork. He says he did it for the first time and accidentally shot on camera"

Sagawa Express announced that it will re-educate its employees to get higher professtional ethics.