Examiners should not have made the comments, the OCR board said at an exam appeal board hearing. But an appeal from Merchant Taylors school, Northwood, north London, that the marking procedure was poor, was dismissed.
At the hearing Tony Orgee, OCR's policy division manager, said: "We very much regret that comments on the scripts were inappropriate and fell short of the quality of marking we expect."
Jon Gabitass, head of Merchant Taylors, a pound;3,250-a-term private school, said marking had been chaotic, bungled and inconsistent. Results for 18 Latin papers were published late because a re-mark was required after the examiner was found to be inadequate. Further alterations were made three months later, when one grade was altered from D to C.
Mr Gabitass said GCSE results fell significantly short of school predictions, marks were insufficiently detailed, rushed and did not credit sophisticated responses.
Last September he requested the papers be marked a third time by a principal examiner, but no alterations were made. He sought an inquiry in May but OCR dismissed his complaints.
The board received a further six inquiries from other schools into marks for GCSE Latin but has not changed any of its original grades.
Merchant Taylors made a second appeal on behalf of Lyng Graham Taylor, now at Cambridge University, who believes he should have received a higher mark on his AS-level Latin paper, despite achieving an A grade. He was one of 34 students in Britain who queried marks for this exam.
Mr Orgee said an appeal hearing was not the appropriate place to question the marking scheme. But he said the exam board regretted "the shortcomings and errors because of changes made" after the Tomlinson report.
The appeal panel did not uphold either claim. Its reasons will be published next month.