The state will have to prove its case beyond a resonable doubt. That's a fairly high standard.
If the rumors are true, it very well could be proved.
I have only heard rumors about what actually happened from someone that was involved to a degree and there is more involved here than what is being made public right now. Since they are only rumors I won't repeat them here, but if they turn out to be true then I'm sure most of us will hear about and discuss this one for a while. This may be one we just need to sit back and watch.
Some of the rumors are already being discussed on this board and other boards.
1.) That she wasn't actually certified to teach open water
2.) that she wasn't actually in the pool with the students when she had divers/students in the water.
I'm not sure what's true and what's no. I wasnt there. But IF either of the above is true and someone died from actions resulting from it, I would think that it would be enough to warrant a Grand Jury of finding reason to go forward with trial.