Apologize for what??
And, as far as your rights go, do you really want a situation where teachers and students can't discipline kids without calling in a parent? Again, had the student been charged criminally, or given a suspension, I could possibly see the need to call you in. However, for what, again, amounted to a "talking to," I just don't see the point.
I am going to recommend to my Governor we stop charging criminals so we can just keep them in confinement without worrying about trials.
Different situation. The child was not confined for years, days or even, I suspect, hours. What happened here is more akin to telling a child to stay in his or her seat during class or going to detention than a false arrest.