{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
Slang English vocab. Английский сленговый словарь. 2012