Contradiction with Exodus 20:13
Judges 3:21 describes Ehud killing Eglon, whereas Exodus 20:13 commands, "Thou shalt not kill," which contradicts the act of killing.
Exodus 20:13: Thou shalt not kill.
Contradiction with Matthew 5:44
Judges 3:21 depicts an act of violence, while Matthew 5:44 teaches to love your enemies, which contradicts harming them.
Matthew 5:44: But I say unto you, Love your enemies, bless them that curse you, do good to them that hate you, and pray for them which despitefully use you, and persecute you;
Contradiction with Romans 12:19
Judges 3:21 involves Ehud taking vengeance into his own hands, while Romans 12:19 advises, "avenge not yourselves, but rather give place unto wrath," contradicting personal revenge.
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.
Paradox #1
The moral conflict in Judges 3:21 could be seen in the act of violence committed in the verse. While some parts of the Bible promote peace and forgiveness, this verse describes a violent action, which might seem contradictory to those teachings.