Handle a hard-headed person

It is really hard to handle a person like that but i have an example for you. My boyfriend has a friend who is just like that. even when he is drunk he still drives even long distance. for how many years no accident happens to him. that guy also told us that sometimes his eyes began to close without knowing it but still manage to go home. until last week. he was drunk and tired from playing basketball when his car got smash a light material house luckily no one got crushed. the house has 3 dividers the first and the 3rd is a bedroom and in the middle is the living room. luckily he crush into the middle. so right now he dont drink and drive anymore. so sometimes when no bad things happen to them they will not realize that what there doing is wrong. so i hope as a friend dont let her drive when shes drunk. but i know its hard as a friend.