re: Laremy Tunsil's step-dad has a prior domestic violence charge against him

That is not a logical assumption at all. He may very well be hoping to gain monetarily from all of this, but he is not going to gain anything by lying to the NCAA. If he was merely threatening to speak to the NCAA in hopes of extorting money from Tunsil or some UM boosters then I would agree with you, but he already had a meeting with the NCAA.

He might be lying, but the fact that he may have sold pictures of himself to TMZ does not reflect on his credibility at all.