Campbell said immediately after the incident it was as if “the red mist lifted” and he and Turner went into a nearby common room and sat down at a table.
He told the court he was still sobbing.
The presenter said he told the teacher “I could call the police on you for that” and that the teacher appeared “chastened.”
Campbell said he went home with a torn shirt. He told the court his mother saw he was “distraught” and called the school.
Following this, he said there was “correspondence” and that he remembered his mother later saying that Turner had been “dealt with”.
Later in his evidence, Campbell told the court that he saw his Edinburgh Academy pupil file for the first time three or four weeks ago.
Asked if there was any record of this incident in it, he replied: “No, it was ridiculously scant.”
Campbell will continue giving evidence on Thursday.