With respect to Trump telling Sondland "I want nothing" (which was used/repeated as a defense by other Trump allies), an opinion piece in the Washington Post claims that this might be a Trump pattern when he (really) wants something politically iffy or downright illegal:
What we’re hearing is that Trump basically said: Lemme be clear, this isn’t a quid pro quo. But Zelensky’s gotta do what I need here. And he’s gotta do it all on his own. Otherwise, we’re kinda stuck, you hear what I’m saying? But lemme be clear: This isn’t a quid pro quo. Got it?
Indeed, Sondland himself has all but confirmed that this is how Trump communicated to him. In his own testimony, Sondland described it this way:
“He said: I want nothing. I want no quid pro quo. I want Zelensky to do the right thing," Sondland testified. "And I said: What does that mean? And he said: I want him to do what he ran on.”
In other words: I’m not telling Zelensky what to do. He needs to do what I want him to do all on his own. He ran on fighting corruption, right? So when will he do what he promised and investigate the corruption of the Bidens?
This isn’t the first time we’ve heard this. Here’s how former Trump fixer Michael Cohen described Trump’s crime-boss vernacular when testifying about Trump’s negotiation of a real estate project in Moscow during the 2016 campaign:
Mr. Trump did not directly tell me to lie to Congress. That’s not how he operates. In conversations we had during the campaign, at the same time I was actively negotiating in Russia for him, he would look me in the eye and tell me there’s no business in Russia and then go out and lie to the American people by saying the same thing. In his way, he was telling me to lie.
It is very likely that this is exactly how Trump communicated that Sondland should convey the demand — which is basically a solicitation of a bribe — to Ukraine. The witness testimony cited above underscores this possibility.
As that piece further comments, sending contradictory messages is a way for Trump to preserve plausible deniability. Actually, it's not the first time a WaPo article has claimed something like that about Trump. Back in 2017:
For President Trump, though, plausible deniability is a way of life. The ability to pretend he didn’t actually say what he seems to have just said is something Trump has weaponized and exploited. It’s something he wields against his opponents in an effort to constantly muddy the waters and rally his supporters against a common enemy.
But the examples in that older article involve Trump statements to the press that might be described as allusions or even dog whistles, rather than what he might have asked other people to do.
As a Columbia Journalism Review article commented:
Trump has forced reporters into the awkward position of trying to evaluate what his supporters might hear. Exact phrasing doesn’t matter. In fact, Trump’s typical word salad provides something of a frontline defense against critical media coverage of his more ridiculous statements. [...]
The reality TV star’s genius lies in a simple trick: He raises ideas while at the same time distancing himself from them just enough to deflect criticism. He establishes some measure of plausible deniability—at least for those who take his statements at face value. Many voters see through this rhetorical ballet, but it poses problems for mainstream news organizations bound by journalistic norms.
So, besides that Cohen example that the later WaPo piece gave, are there any other examples of Trump sending such mixed/contradictory signals in cases where he (allegedly) was hoping for someone to do something?