I have seen many married couples who had so many problems that couldn't be worked out that they decided to divorce. I could never understand how they could get to this point. It was difficult for me to understand how they couldn't communicate with each other. But recently I have had some problems with a friend of mine that I think are almost solely caused by a lack of communication. I have seen how misunderstandings build and grow, and how quickly things can spiral out of control to the point that you don't even know how to fix them.
There are so many aspects to this, it is almost like a spider web that has individual strands crossing over each other, weaving in and out getting all tangled, and once you fall in, you get stuck. One thing happens, then another, and they become intermeshed to the point that you forget when one thing happened and the other ended. It's a blur of little things that may have hurt one of you, or been misunderstood, or misinterpreted.
What I do know is that rarely do people intentionally hurt people they care about. They might say something stupid without thinking that hurts the other person. They might be guilty of acts of ommission; forgetting to do something. The other aspect of acts of ommission is that often people assume that the other person knows their feelings, and gets upset if that person doesn't act accordingly. But rarely, if the friend understands the other person's feelings, will they intentionally do something to hurt them.