Let's start with that first verse - Lev 5:1.
In the RNWT it reads differently to more accurately reflect the true meaning:
(Leviticus 5:1) “If someone sins because he has heard a public call to testify and he is a witness or has seen or learned about it and he does not report it, then he will answer for his error."
So this verse has nothing to do with reporting wrongdoing to the elders - he misrepresented the Bible when he said this. This verse is to do with a judicial case when witnesses are called for. If you know something then you must appear in that hearing.Then the next verse he uses, Deut 19:21.
Jesus referenced this when he said (Matthew 5:38, 39) "You heard that it was said: ‘Eye for eye and tooth for tooth.’ However, I say to you: Do not resist the one who is wicked, but whoever slaps you on your right cheek, turn the other also to him."
So the harsh Mosaic law was replaced by Jesus law of mercy and forgiveness.
Seems this elder doesn't trust Jesus enough to obey his laws instead of the inferior Mosaic laws.
Like most high up elders (instructors) they prefer to come up with their own brand of religious cruelty to treat the flock harshly. They are all invariably detached from human compassion and live to lord it over others.
Elders who still live by the old law reject Christ.
(Colossians 2:13, 14) He kindly forgave us all our trespasses and erased the handwritten document that consisted of decrees and was in opposition to us. He has taken it out of the way by nailing it to the torture stake.