Governments can still be held to account for their civilians. If an American civilian plane flew into China, do you think the Chinese government would be calling the owner of the company? No, you take it up with the government that is accountable for the people responsible.Because it has nothing to do with the Chinese military. It's a civilian balloon.
It's like you who work at accounts having to answer a court summons because Emily from legal filed her documents to the wrong court.
How would the Chinese even know what the phone call was about?