Contradiction with Judges 6:1
Israelites did evil again in the sight of the Lord, contradicting the idea of having peace mentioned in Judges 3:18 after the tribute was delivered.
Judges 6:1: And the children of Israel did evil in the sight of the LORD: and the LORD delivered them into the hand of Midian seven years.
Contradiction with 1 Kings 11:4
King Solomon’s heart turned away from the Lord, contrasting with the suggestion of loyalty or obedience to God in Judges 3:18.
1 Kings 11:4: For it came to pass, when Solomon was old, [that] his wives turned away his heart after other gods: and his heart was not perfect with the LORD his God, as [was] the heart of David his father.
Contradiction with James 1:8
A double-minded man is unstable, conflicting with the implied decisiveness in action shown in Judges 3:18.
James 1:8: A double minded man [is] unstable in all his ways.
Contradiction with Romans 12:19
Believers are told to leave vengeance to God, conflicting with the action of Ehud taking vengeance in Judges 3:18.
Romans 12:19: Dearly beloved, avenge not yourselves, but [rather] give place unto wrath: for it is written, Vengeance [is] mine; I will repay, saith the Lord.