Question For Parents

Would you leave your 2 & 5-year-old in a car alone while you were watching a T-Ball game?

I went to watch Damien's first T-ball practice/game (he's 3) and it was really cold out.  He told his mom and dad that it was too cold, so we decided to leave.  When I was walking to my car, I noticed that a kid who couldn't be more than 2 and another who couldn't be over 5 were sitting a car all by themselves.  I sat there contemplating what to do.  I'm not a parent but I cannot see myself leaving a child alone in a car like that, even if my third child was in the middle of a game.  I am not a parent but I can't see myself leaving a 5-year-old to take care of a 2-year-old.  Is this OK? 

I sat for a long time trying to decide what I should do.  Doing nothing wasn't an option.  In the end, I sat there until both parents got to their car and I got out and said "you shouldn't leave your kids alone like that".  The woman said "these are my kids and I was right over there." My question is, if you were right there and could actually see them, why didn't you come over when the five-year-old got in the front seat and set off the alarm.  I didn't say that but I should have.  Then the dad starts yelling at me how she's a mother of three.  I'm like, OK, well then you should know better.  Right then, I knew I should have called the police.  I don't like to start things but I am not the type of person who can just walk away and hope for the best.  So I tell them that next time I will call the police.  The guy starts yelling at me to call his brother/brother-in-law (I don't remember which it was).  There were a lot of people around and I hope that I embarrassed them enough not to leave their children unattended like that.  All I kept thinking was, these kids could be on the 6:00 news as kidnapped.  I just don't understand some people. 

Did I over-react?  Or should I have called the police?

Well, I'm sure I will see them again the next time my nephew plays T-Ball.  That should be interesting.