Frankly, I'm not even sure details matter that much, really. What actually happened was smaller acts of aggression that escalated step by step. It was totally uncontrollable. There was a huge amount of hatred on all sides. And nobody had any idea how to stop it. For everybody outside it was completely senseless killing, there was no real reason for it. The UN mission was a total failure.
Then NATO came with the idea of bombing but they were afraid to fly too low so apart from bombing the military they also bombed civilians. Many people in Serbia remember this and Putin loves to remind everybody of that. When you dig into it you only discover ugly things.
The UN mission was also spineless and a proximate cause of a lot of trouble. It can be seen in the few instances where UN troops stood their ground, it had good results.
Then NATO came with the idea of bombing but they were afraid to fly too low so apart from bombing the military they also bombed civilians. Many people in Serbia remember this and Putin loves to remind everybody of that. When you dig into it you only discover ugly things.