I'm a HS and MS nurse and seen this. Cell phone are no-no in both schools
, using them gets you an automatic detention. Just the other day, I had the main office call down to me to ask me to send up a student because dad was here to pick the student because they were sick. That student hadn't stepped foot in my office at all; a look at the student revealed nothing was wrong. The parent didn't care. The principle, however, did. The student left, but left knowing she would be receiving a 0 for all the work she would be missing for the reminder of day because this was an unexcused absence.
I always call up to the office when I am dismissing a child home sick, so they know when a parent comes to pick up a "sick" kid and they have not heard from me, that it may be suspicious. My job is keep kids healthy and in school, and I have crackers for nausea, juice and applesauce for students missing breakfast. I'm tough and most parents appreciate it, actually