You haven't given any evidence that Comey ever had a conflict of interest in any kind of sense where a recusal would be appropriate. His family may have political views (though a quick Google search shows no controversy that I can find), but he was never making decisions as FBI chief on things related to their work. That's clearly not the case on Thomas, who was the only one to vote to protect the texts from being released when they related to his wife. That's clearly a conflict of interest. The fact that he failed in his efforts is not really the point and I think you know that. Recusing from the case would have been appropriate, just as KBJ promised to recuse on an upcoming case related to Harvard.

Of course Thomas isn't going anywhere for the same reason that Clinton and Trump weren't going anywhere: politics. For the record, I think Clinton and Trump both did enough to warrant removal from office. I think we'll continue to learn more about Thomas, so I'll reserve judgement on whether he should be going anywhere until we have more details. Sadly it's an academic exercise because we don't hold political figures to the same ethical standards that we do the civil servants who work for them.