You know, I was all for the coach's challenge when they instituted it at the beginning of last year, but what I've seen of it thus far this seasons is a failure, and somehow it seems to have led to even more reviews. They've clearly made it a substantial threshold to overturn a call just to "pad their stats" and protect the refs, as I can recall numerous calls that were obvious upon review that they tried justifying with incidental or minimal contact that no reasonable ref would call a foul.
The whole officiating game needs majorly overhauled at this point. There is just way too much foul hunting going on now, which is a direct result of all of the rule changes to prioritize the offensive player and minimize even incidental defensive contact. Have to cut down on these crap foul hunting calls for the offense. Refs should absolutely not be as involved in these games as they are now.