The school I just finished my contract at did allow corpral punishment. Most of the schools in Southern Missouri do.
The problem is parenting or the problem is elementary and middle school teachers - I haven't decided - though I suspect it's the parents.
High school students have figured out that they can do anything and get away with it. You throw paper - you get yelled at but it's a big joke. You do something really stupid and all you get is a 3 day suspension - a great opportunity for you to sit there and do nothing. And schools will say that a kid can't be punished too much because then he'll just drop out.
I got pissed off and thought I'd scare some people a couple weeks ago. I started yelling and kicked the trash can clean accross the room. About 1/2 the kids kids had tears in their eyes from fright and the other 1/2 had tears in their eyes from laughing so hard. They know the teacher can't do anything. This starts as kids talk back their parents at age 5 about not eating their vegetables. Back in my day I learned to respect or else I'd be taught respect

If you know what I mean
As far as the kid with the phone goes, I have no doubt in my mind that he deserved every one of those 10 days. The worst punishment I've ever seen for a phone is 1 day detention - which is nothing.
The student could be "learning disabled" in which case a 10 day suspention sounds too much.
I suspect the kid was just trash plain and simple. I'm one of the few teachers who take the traditional approach that - you sit down and you be quiet for 9 months, take your F, I'll see you in summer school, I'll give you your D - and if you don't like it you can get the hell out right now and collect welfare like your deadbeat parents. I don't care if you fail - but I care if you prevent others from learning.
All too often teachers think they can help students like this and all it does is give the teacher a big headache.