v. phr. To be fair, even to someone who is bad; tell the truth about a person even though you don't like him, I don't like Mr. Jones, but to give the devil his due, I must admit that he is a good teacher.
GIVE THE DEVIL HIS DUE
Meaning of GIVE THE DEVIL HIS DUE in English
American idioms English vocabulary. Английский словарь американских идиом. 2012