Linked. Per the report:
The FBI had started an investigation into the Clinton foundation which had had not disclosed publicly. This was during the 2016 election. McCabe was being personally criticized that the FBI was doing nothing to look into the Clinton foundation because of his wife’s political affiliations. He apparently authorized others to leak the existence of investigation to the press, And then when asked later several times under oath and not Underoath whether he leaked the information he said he didn’t but did not offer that he had instructed others to do so.

That didn’t deserve at least in most peoples opinion being fired and losing his pension on his last day of employment before retirement. Basically he sued to get his pension back and the government agreed to give it back.