Well having 25 years of experience I would disgaree with much of this. I am willing to bet he is overtrained. The amount of volume is different for beginners. If he is light or trying to gain weight, he could easily be overtrained. If he is a bigger man, trying to lose maybe not so much and he could be at a mental block. No offense but I could not possibly believe any good bodybuilder especially not any powerlifter worth a grain a salt will ever tell you benching 3 times a week is good to gain size or strength.
That once every ten days is an old time trick. Its not a permament one, but it would definately help if its a mental one. I gave some advice based on many many years of training. I am in my 40s with the body of man 30. I have had the good fortunate to train with a couple state level bobybuilding champions, several top east coast powerlifters as well over the years.
Its hard to give good training advice when you don't know the person face to face. As I said I wouldn't lighten the weight, I would suggest a couple less sets or change in routine to get away from a possible mental block.
Let me also add this one note, I could see a bodybuilder benching 3 times a week getting ready for show, but he won't trying to move more weight like this young man here is trying to do.