From what I read in the article, the instructor grabbed him and indicated the need to do a safety stop, but did not "forcibly hold" him underwater after that.
As I wasn't there, I'm not in the court getting the testimony, etc., I'll reserve judgement.
A student that was out of air twice, but currently with air at 5m and a working regulator, after doing a deep dive, should generally conduct the safety stop. What precisely the instructor did or did not witness, and their reaction to the situation they saw, could very well have been "appropriate" or "reckless" depending on the details. Details we don't see in such an article as was linked.
That's my thoughts on the matter anyway, based on what I read.