McCain’s Syrian Adventure: Should He Be Charged with Violations to the Logan Act?

Here’s an astounding bit of news from The Daily Beast.

McCain, one of the fiercest critics of the Obama administration’s Syria policy, made the unannounced visit across the Turkey-Syria border with Gen. Salem Idris, the leader of the Supreme Military Council of the Free Syrian Army. He stayed in the country for several hours before returning to Turkey. Both in Syria and Turkey, McCain and Idris met with assembled leaders of Free Syrian Army units that traveled from around the country to see the U.S. senator.

Inside those meetings, rebel leaders called on the United States to step up its support to the Syrian armed opposition and provide them with heavy weapons, a no-fly zone, and airstrikes on the Syrian regime and the forces of Hezbollah, which is increasingly active in Syria.

Idris praised the McCain visit and criticized the Obama administration’s Syria policy in an exclusive interview Monday with The Daily Beast.
“The visit of Senator McCain to Syria is very important and very useful especially at this time,” he said. “We need American help to have change on the ground; we are now in a very critical situation.”

McCain’s unannounced visit- one conservative website called it “gutsy”- raises all sort of questions. Is it possible that the State Department could have given authorization for such a trip? 
It would surely have taken an approval by the executive branch. Think about it. A high-ranking official slipping across the border of one NATO country into another country in the midst of a bloody civil war? (Could there be grounds for another Issa investigation? Obama "scandals" are being sold to the gullible press at a dime a dozen nowadays.)
Reuters adds this:

The White House had no immediate comment.

A senior State Department official, in Paris with Kerry, confirmed that McCain did "cross into Syrian territory" but referred all questions to McCain's office. 

That suggests the trip was not authorized at all. The Secretary of State would surely have supplied further information if he had any. That implies that McCain took it upon himself to traipse into the messy conflict. A thumbing of the nose to the president, as it were. If true, then it raises some serious political and diplomatic questions.

Firstly there is the sticky question of legality. Did Senator McCain make it clear to the leaders of the Supreme Military Council of the Free Syrian Army that he is in no way authorized to speak or to make promises or to negotiate on behalf of the United States? 
His statements have no more weight than, say, Angelina Jolie. The statement by General Idris doesn’t suggest that McCain made that clear.

There's another question. Did John McCain commit a felony by violating the Logan Act, which forbids anybody but the president (or anybody the president authorizes) to conduct foreign policy.