You just barked up the wrong tree my friend. You never put your garbage cans or bags in your neighbors yard under any circumstances. I was also the President of a Condo association. No one gets away with this kind of crap.
I have been on this street for over 14 years......none of us would ever consider dropping any garbage bags on a neighbors lawn.
So it is strewn across my front lawn and I rake it up and put in a pile in the perpetrators lawn?....that my dear is not petty, its called just deserts!
Social skills would include not dumping your trash in front of someone else's house to be picked up...
I wouldn't want you for a neighbor. When you have a problem with a neighbor, the wise, amicable, and peaceful thing to do is to confront them face to face and work out a solution. What you did is passive aggressive and engenders hard feelings and hostilities, regardless of who's at fault.