Is your kid going to save the day with a cell phone? Do you think in that situation there is not going to be another adult who can call 911?
When you tell your child “just get in trouble and I’ll take care of the rest” you are telling the child that they don’t have to respect school rules. And having dealt with parents like you, your children turn out to be absolute terrors. (“Im texting my mom!” as you hear the fucking Rizzler song for the sixth time)
As part of my teaching training, I was in a program where I was not allowed to have my cell phone on me at all. 6 am to 9 pm, for almost two weeks. I survived.