an odd encounter

If anyone has seen my photos in here, they see my beautiful dogs.  One of which (Jake), I adopted from the shelter.  He is mine and the black pup is my daughter's baby.  My daughter and Joe left for a few days to visit some friends.  Today, after a rough day at work because it was incredibly sunny and beautiful outside and I was stuck indoors, I was looking forward to a wonderful walk as the day drew to an end.  We walked for about an hour or so and then headed home for dinner.  After filling our bellies and relaxing for a bit, I decided I couldn't put aside my craving for a little bag of Milano cookies.  We hop in the car and head to the store.  I pulled into the parking lot, cracked my windows and got out of the car after telling Jake to sit and stay.  There was a truck parked next to my car with two guys sitting inside.  As I locked my car, the guy in the passenger side yells out his window at me that it's animal cruelty to leave my dog in the car.  I smiled at him and said I'd only be a minute and not to worry.  I went inside the store and felt a bit uneasy at what he'd said.  I hurried and not three minutes later was heading to my car.  As I unlocked my door, he yells out to me that my dog had been barking at him.  That he was unhappy in the car.  I said he's okay now, don't worry about it.  He starts going on and on.  I regrettably just stood there, letting him continue talking instead of just getting in my car and leaving.  I asked him if he had a dog and when he said yes, I said well, then you know they like to be with us, that's why he's here.  I asked him to just leave me alone and as I began getting into my car, he just keeps cursing at me and yelling.  Then he yells at me that the next time he sees my car with my dog in it that he's going to take him.  Needless to say, my heart was racing and I could feel my temper just getting hotter and hotter.  I waved and smiled at him as I left but felt like I wanted to ram his truck with my little car.  Why do people deliberately bate one another?  Why had I responded?  Why couldn't I just ignore him and leave him to his own terrible devices?  I look at Jake and know that he is as spoiled as a dog can be.  But that ignoramus actually made me doubt for a split second.  I purposely took him because the evening was cool and I knew that he wouldn't be hot.  I had to run around my parking lot a few times to get my temper under control.  I don't like negative and odd encounters....