A.T. Robertson Commentary John 18:30

"They answered and said unto him, If this man were not an evildoer, we should not have delivered him up unto thee." — John 18:30 (ASV)

If this man were not an evil-doer (ε μη ην ουτος κακον ποιων). Condition (negative) of second class (periphrastic imperfect indicative), assumed to be untrue, with the usual apodosis (αν and aorist indicative, first aorist plural with κ). This is a pious pose of infallibility not in the Synoptics. They then proceeded to make the charges (Luke 23:2) as indeed John implies (18:31,33). Some MSS. here read κακοποιος (malefactor) as in 1 Peter 2:12,14, with which compare Luke's κακουργος (23:32f.; so also 2 Timothy 2:9), both meaning evil-doer. Here the periphrastic present participle ποιων with κακον emphasizes the idea that Jesus was a habitual evil-doer (Abbott). It was an insolent reply to Pilate (Bernard).