When asked about Flynn's pleading guilty for lying to the FBI, Trump made the usual excuses. Then he sent a tweet, reportedly written by one of his lawyers:

I had to fire General Flynn because he lied to the Vice President and the FBI

Where this gets problematic, of course, is that it's been well established that Trump asked then-director of the FBI Comey to go easy on Flynn. So his new statement is that he knew Flynn had lied to the FBI at the time he asked Comey to back off. As a former head of the Office of Government Ethics responded:

Are you ADMITTING you knew Flynn had lied to the FBI when you asked Comey to back off Flynn?

He would then add:

Before we slipped into an alternate universe of unabashed corruption, this tweet alone might have ended a Presidential administration.

Another commentator said that

This is a pretty substantial confession to essential knowledge elements of an obstruction of justice charge.

Meanwhile, the overall plot thickens further:

Meanwhile, an email written by a Flynn deputy that came to light Saturday suggests that many of Trump’s closest aides were informed that Flynn planned to discuss sanctions with the Russian ambassador before Flynn made a December phone call to Kislyak.

(The second tag explained.)