That is one of the worst betting scandal that had happened in the NBA, and I remember as well the brother of Michael Porter Jr of the Nuggets also involving himself.
Here, though it's the coach that is being accused so it's hard to show proof though, unless the NBA makes it's own investigation. So let's see if they will do it or not because it seems that there is a cause for them as it is controversial.
Agree to that unless NBA will take this seriously and make their own investigation there might be a possibility but if there's no action then we might see that the issue will die naturally and the system will continue, betting scandal as you mentioned is no longer new officiating refs has been suspended because of these kind allegation.
Though in that sequence, I do agree from the post above te coach wa calling the timeout before Sexton penetrates inside he was beside the refs calling it, but we can't blame those bettors as they've got the chance winning the game if the coach risk that play, though not similar butI remember how Heat lose a game after coach Spo call a timeout and got the technical becuase they don't have any timeout left.