There are times you may have to face this miscommunication problem. You're ultimately dealing with people. People think and act differently from others and can change, whether good or bad, whether temporarily or permanently. Some people can be overloaded at work, causing much stress. Some people have obnoxious personalities that can get on other people's nerves.
People can misinterpret the other's intentions.
For example, when a department says that they have the authority to require something without having to explain why, it probably should just mean that. Yet, the receiver can become absolutely offended. Some of you may understand that the department was not trying to show power over the other but just wanted to express the thought that they have the right to do something and that the other department shouldn't require them to do something that would seem contrary to that. Sometimes we write with unintended meanings. We all have to try and communicate better.