Oh yes it is...
. I couldn't see his left hand, however, he would have been unable,.I'd have thought...to hold anything..drink, food or mobile phone in that hand. As for changing gear I have to assume it was an automatic but re changing gear in normal driving..ie both hands on the steering wheel then,obviously, in that moment only one hand is on the steering wheel of course but for seconds. There's a huge difference between changing gear and thus driving for seconds with one hand on the steering wheel and driving along with the right arm dangling down the side of the car...especially whilst making a right turn. I don't recommend you try this but suddenly having to brake whilst holding the steering wheel with one hand is very likely to lose even more control of the car.Instead of the car infront stopping unexpectedly what if a child ran out into the road infront of this car. ?
Anyway,I wouldn't be comfortable making a right/left turn using only one hand on the steering wheel. What if he had to suddenly turn the steering wheel more to his right than he anticipated and he was at his limit stretching his left arm across his chest ? Too late to whip his right arm in and onto the steering wheel to assist.
Have a read of this article (link below) . As you see at the start of the article the insurance company Ensure have said that 2 million drivers have had an accident or a near accident whilst the driver was driving with one hand with one hand. 2 million !! It doesn't state over what period. Included are some results of an academic report that was published in 2012 regarding driving a motor vehicle with one hand. One finding was that whilst driving with one hand on the steering wheel it takes twice as long to stop if the vehicle infront suddenly stops than if the driver had both hands on the steering wheel. It gives more examples of problems.
According to esure, two million drivers have had an accident, or near accident while driving with just one hand.
www.autoblog.com