Is there really any credibility to Obama's claims on recess appointments?

Here is a brief note over what the Obama administration was arguing just over a year ago. From Fox News:

critics are pointing to another legal memo from the Justice Department that they claim is in conflict with the one issued Jan. 6 - and it comes from one of Obama's allies. In 2010, then-Solicitor General, now Supreme Court Justice Elena Kagan authored a letter to the Supreme Court Clerk's Office with respect to recess appointments. While noting the president does have authority to make such appointments, Kagan added "... the Senate may act to foreclose this option by declining to recess for more than two or three days at a time..." In her Jan. 6th memo, Seitz addressed the 2010 Kagan memo and determined that it was not on point. . . .