RCHS is absolutely lottery based. They are very much above board and follow the letter of the law exactly. So does Magellan. They are probably two of the best and most efficiently and honestly run charters in the state of NC. The people you are hearing from are misinformed. There are plenty of laws getting broken at charters, and it is easy for them to get away with some pretty scary things. However, lottery trickery is very uncommon. I once saw a school get threatened with a lawsuit because a parent swore that they saw their kid's lottery number stuck inside the basket from where the numbers were being drawn. From 50 feet away.
That was many years ago, and since that time, the process is better organized and is probably watched more closely than most charter operations. Frankly, charters that are looking to scam have much "better" and easier ways to do it.