The Douchebag Next Door.

I met the biggest douche bag on the planet, no scratch that in the universe.
Rewind. Rewind. Rewind.
Wednesday night myself, J and our friend decided to take the dogs for a night walk. It was probably about 11pm and Shia and Indie were acting restless, we needed to tire them out, so we decided to take them on a long walk for some additional exercise. We leashed them up and started walking. We made it about 5 houses down and Shia started to do the poop squat. We have doggy bags that hook to her leash. I went to grab a bag and it was empty.
A car pulled in where Shia was still pushing out her business. I was talking to Jared as the car pulled up. I asked him if he had any bags, he didn’t. Meanwhile, Shia is still squatting. I told Jared, we need to walk back and get the bags so we could clean up the nasty.
Shia finishes. The car door opens. We start making our way back home to get bags. This late twenties dude leans his head out the passenger door and screams “She (the young woman driving) doesn’t appreciate you leaving dog shit on her lawn!”
I started to walk over to explain the misunderstanding. He slams the door. Ok… So once again, we head back toward our house. He once again leans out and says “she loves shit on her lawn!” and I reply “We’re going to get a bag, we ran out. If you have one - I’ll pick it up right now.” He sticks a plastic cup out the window.
“We’ll be right back, we’re going to get a bag.”
He finally steps out of the car and starts rattling off again. At this point I’m really irritated. I screamed back “Don’t be an asshole, we’re going to get a bag right now.”
Then the girl gets out of the car and says “Listen… we’re a bit drunk, sorry..” She starts to push her boyfriend toward the house. He is still yelling at us and telling us not to worry about, because he loves picking up shit and will happily clean up after our dogs.
I can’t express how irritated I was at this point. Of course, we walked the 5 houses back to our own and grabbed a bag and cleaned it up like we were planning to do the entire time. Instead of throwing it in the trash, I wanted to light it on fire and leave it on the front porch, but it went in the trash.
Why are some people so ignorant and rude? I’ll never understand what made him react like that, instead of just saying, “do you mind picking that up?” and then we would have said “Of course, we just ran out of bags and we’re headed back to grab them right now.” BAM! Conversation over.
I’m sure that guy gets in a lot of fights.
What would you have done in my situation?