Caporegime
From the boss's point of view, I can't see how he would admonish the team leader for the manner in which he dealt with this. If the OP's only crime was not turning round and driving the employee all the way back home again then reporting it when he got back to work, then he's done nothing wrong.
The other point that Castiel is missing is the benefit of having an employee on site when an issue like this is raised. It's far easier to judge a situation when the accused employee is standing before you rather than on the other end of a telephone. A boss can read facial expressions, better gauge reactions and levels of remorse, hear any explanation 'from the horse's mouth', even smell his breath and assess if he really is drunk or not.
The other point that Castiel is missing is the benefit of having an employee on site when an issue like this is raised. It's far easier to judge a situation when the accused employee is standing before you rather than on the other end of a telephone. A boss can read facial expressions, better gauge reactions and levels of remorse, hear any explanation 'from the horse's mouth', even smell his breath and assess if he really is drunk or not.