The intimation in this story is that Mexicans smashed this kids skull in while he was sleeping in the pool area of a luxury Cancun Hotel. This is very unlikely. Mexicans might kill you, under a lot of different circumstances, for any number of reasons. This scenario is highly unlikely. They wouldn't do it in the courtyard of a high end tourist hotel. They never would have left the kid alive to potentially recover and tell his story.
This kid was involved in some terrible mishap involving other vacationing American kids. It may or may not have been with malicious intent. It probably was an unfortunate and unforeseen alcohol related calamity, that none of the others involved in wanted to own up to.