I believe that on June 8, the Justice Department issued a statement showing that Mr. Sessions' recusel was required under 28 CFR 45.2, primarily because he was closely affiliated with the Trump campaign which was under investigation. After reading the actual law on the subject, it is apparent that he would have needed to recuse himself whether or not he had met with a Russian ambassador. It was his position with a political campaign subject to investigation that was the determining factor.
On the subject of recusel, it is interesting to note how many time recent AG have recused themselves.
Reno - 2
Mukasey - 2
Gonzales - 2
Ashcraft - 3
Holder - 4
Lynch - 0 ?
Sessions - 1
the text:
no employee shall participate in a criminal investigation or prosecution if he has a personal or political relationship with: (1) Any person or organization substantially involved in the conduct that is the subject of the investigation or prosecution; or (2) Any person or organization which he knows has a specific and substantial interest that would be directly affected by the outcome of the investigation or prosecution.
Trump has never been under investigation, at least not until Comey and Mueller ginned up something over Comey's firing and Trump's comments to Comey about Flynn. This was confirmed three times by Comey.
There has been a counterintelligence investigation into supposed Russian hacking of the DNC and Podesta and other entities.
As a part of the counterintelligence investigation, the intelligence agencies looked at contacts between Russian officials and people associated with the Trump campaign. After months and months of this by partisan Obama hacks in the intel agencies, they STILL could not find the basis to initiate a criminal investigation of Trump or anyone associated with his campaign having to do with the Russian hacking.
There has been NO criminal investigation of Trump people with respect to Russian hacking that would at the outset invoke a question as to whether 28 CFR 45.2 applies here.
There does appear to be some type of criminal investigation going on in the EDVA as to Mike Flynn's registration as a foreign agent for Turkey and perhaps as to Manafort's activities in Ukraine from years ago. There are rumors that they may be investigating Flynn for misstatements to the FBI.
One could argue about whether Sessions had some sort of relationship with Flynn or Manafort sufficient to warrant recusal into these matters.
But there was not prior to the appointment of the Special Counsel a criminal investigation of the Trump campaign related to Russian hacking. So there was no basis for a recusal by Sessions under 28 CFR 45.2, and it was premature.
Now, today, there are legitimate questions as to whether Sessions should recuse related to presumably criminal investigations ginned up by Comey and Mueller over Trump's firing of Comey and comments regarding Flynn. But none of that had happened at the time Sessions recused himself.
Also, Rosenstein's appointment letter of Mueller was inappropriately vague and insufficiently connected to a probable crime for investigation. Having a "link" with Russia is not a crime. If there was to be a Special Counsel, then the appointment letter should have specifically referred to criminal hacking allegedly by the Russians and the investigation of any actual crimes such as conspiracy that may have occurred related thereto.