Re: an alleged Nazi salute
It is clear that he made the gesture, but that isn't enough for newspapers to call it a "Nazi salute". There are two reasons for that. The phrase states, not just an action, but an intention. A paper could easily justify calling it a "Nazi-style salute", meaning only that it resembles one, but if they call it a "Nazi salute", then they are stating that he agrees with Nazis. A lot of newspapers have standards which basically forbid making such statements. They can say it looked like one. They can say that Nazis interpreted it as one. They can say that a lot of people thought it was one. They can say that Musk's actions suggest it was one. But while he is saying that it wasn't one, they're likely to stick an "alleged" in there to indicate that the intent was not proven, because there remains some chance that he had something else in mind, even if that chance is unlikely.
This is partially due to journalistic standards, but it is also because, if they suggest an intent, they can be sued for defamation. Not necessarily successfully, but it happens and the journalists don't always win. Musk is frequently litigious, and even though many of his cases fall somewhere in the range from dubious to obviously going to lose, it is a prospect that some papers don't take lightly. That is not the only reason why they may choose not to say it, but it is certainly one of them.