The argument "Person A in situation X therefore also Person B in situation Y" is a poor one unless you supply strong supporting explanation.Do you not remember them trying to impeach Trump over a pressure campaign against Ukraine, and when we got to see the actual messages between the people allegedly tasked to carry out that campaign, the first discussion they had about it was in response to news reports and basically said "wait, do they think we're doing that? I'm not doing that!"
Besides:
in his memo to Mr Johnson, Sir Kim wrote: "The outcome illustrated the paradox of this White House: you got exceptional access, seeing everyone short of the president; but on the substance, the administration is set upon an act of diplomatic vandalism, seemingly for ideological and personality reasons - it was Obama's deal."I see little reason to believe a UK ambassador has deeper insight into Trump's intentions than his closest subordinates, and I don't see any reason in this era to not think government officials are just reporting what they read online.
Secondly, I think you're seriously misleading us to the point of dishonesty to claim that the people who where were saying "I'm not doing that" over Ukraine were Trump's "closest subordinates".