Update: This is very different than the first report — and Burr’s original contention:

BREAKING: Senate panel says it has not received response from Michael Flynn's lawyer, correcting earlier comments from chairman.

— The Associated Press (@AP) May 18, 2017

As Emily Litella said … never mind!

Original post follows …

Want to know why Donald Trump’s lawyers and advisers urged him to refrain from contacting Michael Flynn? This is why. A few weeks after reportedly sending a message to Flynn to “stay strong,” the former national security adviser has decided to defy a subpoena to testify at a Senate Intelligence Committee hearing.

If anyone’s looking for circumstantial evidence of interference …

BREAKING: Top Republican on Senate intelligence panel says Michael Flynn's lawyers say he won't honor subpoena.

— AP Politics (@AP_Politics) May 18, 2017

Fox News also reported it, nearly simultaneously:

BREAKING NEWS: @AP: Top Republican on Senate Intelligence Panel says @GenFlynn won't honor subpoena. pic.twitter.com/geAwmpuNH9

— Fox News (@FoxNews) May 18, 2017

Committee chair Richard Burr says his panel’s not surprised by the development:

A lawyer for fired National Security Adviser Michael Flynn has informed the Senate Intelligence Committee he will not honor its subpoena for private documents. That’s according to the panel’s chairman, Republican Sen. Richard Burr of North Carolina.

Burr told reporters Thursday about the response from Flynn’s lawyer. Burr says the panel’s members are not surprised and says, “We’ll figure out on Gen. Flynn what the next step, if any, is.”

Except that Burr may not have gotten a final answer yet, either, as he himself admitted:

Burr says he may have spoke too soon and that "definitive answer" from Flynn's lawyers hasn't been received yet.

— Laura Barrón-López (@lbarronlopez) May 18, 2017

Here's transcript of what Sen. Burr told reporters after initial comments on Flynn lawyers/docs pic.twitter.com/uT4pQzw4tv

— Laura Barrón-López (@lbarronlopez) May 18, 2017

We’ll get to that in a minute. Just before that news broke, Yahoo’s Michael Isikoff reported on the Trump communication to Flynn in late April:

Saddled with steep legal bills, Flynn wanted to reconnect with old friends and talk about potential future business opportunities. But one overriding question among those present were his views on the president who had fired him as national security advisor.

Flynn left little doubt about the answer. Not only did he remain loyal to President Trump, he indicated he and the president were still in communication. “I just got a message from the president to stay strong,” Flynn said after the meal was over, according to two sources who are close to Flynn and are familiar with the conversation, which took place on April 25. …

The sources who spoke to Yahoo News say Flynn did not indicate how Trump had sent the message—whether a written note, a text message, a phone call or some other method. (The White House did not respond to a request for comment.) But the fact that the two men have stayed in contact could raise additional questions about the president’s reported request to former FBI Director James Comey to shut down a federal investigation into the retired Army general.

Before anyone gets too excited about this development, however, recall that Flynn has been balking for some time about testifying. Flynn demanded immunity at the end of March in exchange for this testimony, a demand which Trump endorsed at the time. Burr rejected the offer almost immediately, with sources telling NBC that such a request was “wildly preliminary” at that stage. This looks like some hard-nosed horse trading rather than a final refusal, especially since further developments around Flynn have put him at more risk of prosecution. He needs protection now more than he did two months earlier, and his lawyers are certainly not going to let him testify under oath or not (in Congress it makes little difference) until they know his testimony won’t get used against him for any other purpose. That’s why this is almost certainly not a “definitive answer.”

Defying a subpoena has its risks, too — contempt of Congress can carry a one year prison sentence and a $1000 fine, as Emily Singer pointed out today. That may also have some impact on Flynn’s standing as a retired command officer in the Department of Defense. However, a contempt decree also requires a federal prosecutor to take up the case, as we discovered when Eric Holder got slapped with a contempt decree from Congress, and that may not be likely in this administration. Flynn could show up and just take the Fifth, but that’s going to look dreadful. Hence, he wants to negotiate a safe passage through Congress, and hopefully preclude any other action as well.

The history here — and the distance between the “stay strong” and this refusal — makes Trump’s communication look less like interference and more like an inability to discipline himself. But this should serve as a reminder to Trump that lawyers instruct their clients to refrain from contact with witnesses, potential or otherwise, in the midst of investigations for very good reasons. As much as Trump might personally like Flynn, contact between the two of them while this investigation continues could open up all sorts of charges about interference and tampering, and it won’t take much more of that before Trump might provoke a revolt on the other end of Pennsylvania Avenue.

This is worth remembering, too:

https://twitter.com/redsteeze/status/865232747874353152

Update: It took me a bit to find last week’s story on legal advice to Trump about contacting Flynn, from The Daily Beast:

White House lawyers have had to warn President Donald Trump repeatedly against reaching out to his fired National Security Adviser Michael Flynn, two people familiar with the matter tell The Daily Beast.

Trump, angered by press coverage of the Russia investigation and Gen. Flynn, has asked senior staff and the White House counsel’s office multiple times if it was appropriate to reach out to the fired National Security Adviser, according to a source close to Flynn and a Trump administration official with direct knowledge of the exchanges.

I added the link to the lead paragraph as well.

Update: Popehat — not exactly a Trump fan — dismisses the issue of the “stay strong” message:

Because if you don't clients will ignore your requests and issue unsupervised, undisciplined, rambling messages of support. /2

— IncitementToResurrectionHat (@Popehat) May 18, 2017

So Trump sending a brief, generic message of support isn't necessarily an OMG thing. /3

— IncitementToResurrectionHat (@Popehat) May 18, 2017

True legally, but politically it might be another matter. When your attorney tells you to keep your mouth shut, just remember why you’re paying him or her in the first place.