Unbelievable! Sorry you went through that, Bob. I would have choked on that situation.
I agree with someone earlier who said, "...it's about gratitude for a gift."
When my two sons were little boys, my wife and I taught them strictly to make certain they showed extreme gratitude for any gift from anyone, anytime. So if they opened a Christmas present from grandparents with a pair of socks inside, they had BETTER make a fuss about how much they liked those particular socks, and thank the grandparents clearly and distinctly BEFORE opening any other presents. Even if they really wanted video games, or whatever. I warned them vigorously that if one single present was opened without gratitude being shown, and a pause made for a directly-spoken "thank-you," that I would take away the rest of their gifts for a week. I am proud to say that, even today they understand this lesson well.
I am sorry that your nephew did not. But I suspect that if he doesn't understand this, then he will have several important lessons to be learned in life. And life as an automotive technician is not so easy... That life will definitely teach him many, many tough lessons...the hard way.