Need some advice on a situation while out for 4th

I went out to 4th celebrations with an old friend who was in town.  We decided to hit a couple of bars after the fireworks.  We dated many, many moons ago right out of high school.  I really liked him then.  Since then he's had problems with the law and drinks quite a bit.  The night seemed to go okay at first.  But he got more and more drunk.  He began to wander away at the bar and chat up lots of women.  He would occasionally wander back to me almost to make sure I was still there as I was his ride.  Then back to the wandering and flirting.  After a couple of hours of this I was done.  He was becoming belligerent and disrespectful.  I couldn't tell if he was looking for someone to go home with or not but I certainly wasn't the person he was spending his time with except the rare occasion he came over to check on me.  Finally I'd had it and left.  He's mid 40s and had his own money.  I figured if he wanted to spend the majority of his time working on other women he could get a cab and find his own way home.  Now I feel like a terrible person.  Did I do the wrong thing?  I didn't want to start an arguement about his behavior or have to put up with his drunken anger about not being ready to leave when I'd had enough of being invisible.  It seems like the older you get the more important it becomes to clean house of people that are dragging you down, huh?  Thoughts??