I mean combined with the text messages of these guys pretty clearly talking about an assassination.. just lay that out. Trump said "Take her out", his associates discussed tracking her location, needing to be wary of her security detail, and how you can pay for just about anything in the Ukraine.
Think of their position.
They're journalists. If they say that Trump ordered an assassination of an ambassador - a serious charge - it would be viewed with slant. Provide evidence, conclusive and not a hint of evidence, that Trump ordered an assassination. With the current facts you can't.
A lot of frustrations with journalists will go away when you realize that often they can't just say,"Trump ordered her assassination". That would be the journalists'
opinion rather than a statement of the facts. It would further divide the nation that already does not trust the media. Also consider that journalists cannot be for one specific side. Their job is to report
news. The tweet you're referring is just that: news.
A lot of frustration I had towards the media went away when I realized this. You're frustrated because you want them to confirm your bias - as true as it may be.
In an article, they would bring up a line about some believe that Trump ordered a hit but it's still scuttlebutt and not verifiable.