Interesting, indeed.  If the reasoning was Comey's  mis-handling of the email issue, he should have been gone long before now.  

Firing Comey the day after the hearing with Yates and Clapper, during which the administration appeared in an unfavorable light, and while Comey was in charge of looking into contacts between the Trump administration and foreign nationals, on the recommendations of a man that failed to disclose his own meetings with a Russian diplomat and who has had to recuse himself from investigations related to the Trump campaign, suggests the real reason for Comey's firing now was something else.

The manner in which Comey's firing was handled was absolutely unprofessional, but then most things Trump are.  Comey made some mistakes, but at a bare minimum, he deserved to be the first one to know.