He was trying to teach his son about the possible negative repercussions of lying and how lies can affect other people. What they did isn't really the same thing. In my opinion this is effective parenting and helps prepare the little liar for the real world. So... like... what parents are supposed to do. Much more effective than saying "yo hombre, no hagas eso, ese" , and in our current society, more acceptable than beating the ever loving **** out of him.