Oh there seriously was.. I personally know this first hand.
i've been in chinuch for many years, and I truly hope that this is not the entire picture, as it seems that this was a turning point, and possibly his 'last straw'.
Even with 10 warnings, and
even if he was meeting a girl there, and
even if he was buying something, etc..... (all of which it seems is not the case), there would really need to be a clear meeting with parents, very straight forward understanding, and ideally waiting for a few more weeks until the end of school to do something so negative and so earth-shattering to a teenager...