I call BS. The idiot added someone to a group chat that should not have been added. BS that he didnt know the guy, there are pictures of them together. If signal is anything like webex, you have to type in the name (or phone number) to add someone. That is NOT an accident. At my job, with a lot less consequences than this, if I started a group chat with my team and "accidently" added a customer who then saw us talking about proprietary info in front of the customer, we would get fired. My job is not life and death. I would be willing to bet if this happened under anyone but trump, you all would be ready to lop off his head because he committed treason.