The Wall Street Journal's Kimberley A. Strassel has a clear, unconfused, description of what happened and why his activities were not only okay, but in fact laudable and excellent. If the whole story is TMI for you, see her conclusion:
Mr. Nunes has zero reason to recuse himself from this probe, because he is doing his job. It’s Mr. Schiff who ought to be considering recusal, for failing to do his own.Mr. Schiff is the ranking Democrat on Nunes' committee. He appears to believe his job is defending partisan criminals in the former Obama administration from prosecution.