Richard Halladay, who worked at Alleyn’s School in East Dulwich from 1991 to 2022, engaged in a sexual relationship with a 17-year-old pupil.
The relationship lasted several months during which she would regularly visit his flat.
This did not come to light until an anonymous tip-off was sent to the school in 2021, Mr Halladay was then dismissed from the school six months later.
But last month the Teaching Regulation Agency (TRA) decided he should not be banned from teaching.
The TRA panel found that the “culture was very different” in the 1990s and that at the time there were “no explicit standards in place that would have indicated such conduct was unacceptable”.
The misconduct report said that the current head teacher of Alleyn’s provided a witness statement in which she stated that Mr Halladay’s conduct would not have been viewed with the same level of severity as it is now, and that to a degree, interactions like these between younger members of staff and older pupils was less shocking.
She said that there was not the same understanding of the risk conduct of this nature poses to young people in the 1990s.
After Alleyn’s School received an anonymous tip-off in November 2021, the school arranged for a suitability assessment to be carried out.
An independent safeguarding consultant was tasked with assessing whether Mr Halladay presented a risk to children he had been in contact with and if he was safe to continue teaching.
The pupil he had been in a relationship with was interviewed and she said she would not have reported the matter herself but had told a friend.
She stated she did not “feel a victim” and that Mr Halladay “was not a predator”.
She added that there was no excuse for the relationship and that if someone did it to her daughter she could not put into words how angry she would be.
She described Mr Halladay as “self indulgent, good looking, lots of girls throwing themselves at him, he was innocent”.
When Mr Halladay was interviewed he admitted the relationship and stated he knew it was wrong.
The assessment concluded that “it would be entirely unreasonable to suggest he was not suitable to work with children based on one grave error of judgement nearly 30 years ago”.
TRA decision maker Sarah Buxcey agreed with this conclusion.
Ms Buxcey wrote: “I have concluded that a prohibition order is not proportionate or in the public interest.
“I consider that the publication of the findings made would be sufficient to send an appropriate message to the teacher as to the standards of behaviour that were not acceptable and that the publication would meet the public interest requirement of declaring proper standards of the profession.”
This paper has contacted Alleyn’s School for comment.

