Two incidents in her whole life are not the sum of her as a person.
It really depends on what those incidents are -- for anyone.
For you, your incident, fortunately, ended with things working out between you and your friend. I had a horribly drunken and, from what I was told, super-vomiting, moment when I was a teen and said some pretty nasty things to a friend of mine (my 1st love). We got over it (are still friends now, 27 years later) and, after a few more years of "hard-partying" ways (really, just drinking to get super-drunk because that was fun in my teens and early 20s), I learned not to drink if I were either very sad or very mad so I didn't (drink, that is). These days (and for the past 20+ years), I rarely drink anyway so it's a moot point.
For Reese Witherspoon and her husband, thankfully, they were stopped before their drunken driving could hurt anyone, but she was belligerent and full of herself and wouldn't listen to the police officer. I think she's old enough and has been in the public eye long enough to know better than to behave in such a fashion so, yeah, this behavior makes me wonder.
For the relative of someone I know (a relative who was a public figure), that person's "one" incident of in-the-public-eye drunkenness took the lives of four people (that person is serving a prison sentence now and still won't admit any responsibility for what took place). According to that person's family, that person is a good person.
Reese Witherspoon and her husband were extremely intoxicated and could've killed someone. Yes, this one incident was a very big deal. YMMV.