Did something happen? Why is he suddenly making public statement critical of Trump?
It's likely around the Roger Stone fiasco.
Roger Stone, a long time Trump ally and campaign surrogate, was found guilty of 7 / 7 charges in his trial about lying to congress, witness tampering, campaign finance violations, and other charges. Because Stone also threatened a witness ("Prepare to die," he said) and numerous other violations of good will during his trial, Government prosecutors who report to Bill Barr, recommended a stiff sentence 7-9 years. This is a significant prison sentence for Stone, I know others may want longer, but it was stiff and it was mostly around Stone's behavior at trial. He did other things like Instagramming the face and name of the judge hearing the trial, in and of itself given Stones' explosive allies, something that could be taken as a threat, he violated multiple gag orders, and tried to interfere in Bob Mueller's investigation of Trump.
Barr, through an intermediary, issued a statement that the Government would be officially contradicting their prosecutors, and requesting a reduced sentence. This was made public
on Fox News. Prosecutors found out about this through Fox News, not even from their own department. It was public before the prosecutors even heard about it, despite that they recommended the sentence a day before AND that the recommendation would have certainly been approved by the Justice Dept before they went through with it.
Coincidentally, Donald Trump took to twitter in the very early morning hours -- likely sitting on the toilet -- saying that Stone has been unfairly treated, is completely innocent, and that his recommended sentence was too harsh and not deserved and that he'd do something about it.
As a result, the four government prosecutors who had made the case against Stone withdrew from the trial in protest. One of them actually resigned from the Justice Dept. as a federal prosecutor (which is a low-paying but much sought after role for any lawyer, federal prosecutors often go onto major positions in government -- often times federal judges which may eventually lead to a Supreme Court appointment). This was a major act of protest by lawyers for the government, something that's probably never happened in most of our lifetimes.
If you're interested in a deeper dive, listen to this podcast from Preet Bharara and Anne Milgram, former government prosecutors talk about it yesterday:
In this special episode of Stay Tuned, “Stone Cold Crisis,” Preet Bharara and Anne Milgram dig into some seriously troubling news: The DOJ’s decision to overrule career prosecutors’ recommended sentence for Roger Stone, Trump’s long-time advisor and friend, a day after Trump called the initial...
cafe.com
It's clear that Trump will pardon Stone if he faces any jail time it's just a question of when.