It looks like another great example of avoiding personal responsibility. The student broke the rules and the parents want to blame the chaperones and look into legal action. I asssume that the student had some reasonable amount of intelligence which is probably a big assumption. But, assuming this is all attributed to immaturity, it is not difficult to find your gate number and board a plane to the US at an international airport. If this was overwhelming to him and disturbing to you please do not let him get a drivers license and you may want to sign him up for remedial education or lifeskills. btw, do you let him out of the house
or do you chaperone him?