Yes I have and if you can't contact them at the moment doesn't mean it stops there. Eventually contact will be made and then it should be discussed. The confrontation should be with the parent, not the student. You inform the parent of your suspicion and carry on from there. Inform the student you will be talking to the parents and send the student back to class. Also inform that disciplanary action may be pending after the discussion.
The job of the principal is to get both sides before jumping to any conclusion.