That shouldn't surprise you. Either he's lying, or he recognizes that this admission is basically harmless.
All you Freepers out there who are calling for McCabe to be prosecuted for "treason" or "sedition" because he wanted to remove the President from office under the 25th Amendment should cut back on your coffee intake. There's nothing criminal about discussing -- or even pursuing -- a course of action that is written into the U.S. Constitution.
McCabe is a moron. He probably spent too much time discussing this nonsense with the third-rate lawyers who work as talking heads for the failing cable news networks.
Sorry, I dont think its normal - or constitutional - for federal departments to decide they want to invoke the 25th amendment to impeach a president, particularly since their only reason for discussing this was that they didnt like him and had expected Hilary to win.
Frankly, I think the only reason they backed off and went for a protracted campaign to harass and handicap him was that they realized that Pence would then become president. And I think Pence is definitely less warm and fuzzy and long-suffering than Trump, so they were scared. Of course, next they would have discussed some way of getting rid of Pence too.