James Findlay, for Staffordshire CC, firmly defended the headmaster of Birches Head High School's decision on April 4 that Martyn Ashworth should never set foot in the school again.
He said there was no doubt that Martyn was a 'seriously disruptive' pupil who had been temporarily excluded from the school five times in just 13 months. It was 'repeatedly made clear to him' what would happen if he offended again.
Mr Findlay told Mr Justice Turner: 'To an informed person there would be no doubt as to why the committee reached the decision it did. It is not tenable to say that the saction was disproportionate'.
And Mr Findlay rejected claims that the committee had relied on precarious 'hearsay' evidence from the school's headmaster and other pupils before finding that Martyn had indeed been involved.
The committee had been in the best position to judge Martyn's answers to questioning, and Mr Findlay urged the judge to be 'wary of interfering'.
Ian Wise, for Martyn's mother Carol, argued earlier that expulsion should be used only as a 'weapon of last resort' for the most serious disruptive behaviour.
He denied that Martyn had even been involved in the incident, saying: 'He was with a group of children leaving school following a football match and he was walking through the car park when other children let down the tyre'.
Although he was a 'mere bystander', Martyn was the only pupil expelled over the incident, he added.
Although he accepted that Martyn's past disciplinary record was 'relevant' to the committee's decision, Mr Wise said the committee had been obliged to impose a penalty which fitted the particular offence.
'The committee failed to consider whether the deflation of the tyre was of itself sufficiently serious to justify Martyn's permanent exclusion'.
Government advice to schools was unambiguous that where more than one pupil was involved in an incident, 'using one pupil as a scapegoat should be avoided'.
Mr Findlay told the court that the county council had offered to place Martyn at another school or at Stoke-on-Trent sixth form college.
He said he had been informed that Martyn had already been enrolled at the sixth form college and urged the judge not to intervene for that reason.
But Mr Wise insisted that Martyn's enrollment at the college had not been counter-signed by his parents, as it had to be, and he remained an 'excluded student'.