But Humphrey argued that while he did have concerns around Islamic political extremism and certain immigration rules, any assumption that everything posted reflected his "own staunchly held views is entirely misguided".
"I post on Facebook, not to declare truths I insist everyone should agree with, but to stimulate discussion as a way to challenge and develop my own thinking about difficult and complex issues."
The posts appeared to have only gone to one person.
He also claimed that disagreeing with some aspects of Islam, had "absolutely no bearing" on how he treated individual Muslims and that he had the "mental stability and probity" to separate his political views from his teaching practice which in no way affected the way he dealt with children.
In its decision, the tribunal labelled two of his three posts "ill-considered and undoubtedly inappropriate", as well as a "misguided attempt at creating discussion".
The tribunal disagreed with Humphrey's view that he was trying to stimulate discussion on a difficult issue and felt the "banal" and "provocative" posts were instead aimed at trying to get a rise out of his friend.
It said determining whether Humphrey's behaviour involved serious misconduct had been a "difficult decision" because sending material with racial overtones especially so soon after 51 people were killed in a terror attack in the city affected his fitness to be a teacher and was a definite breach of the code of conduct.
However, because Humphrey had only sent the posts to one friend and had not posted the objectionable material more widely, the tribunal did not find his actions had bought the teaching profession into disrepute and therefore did not meet its high threshold of being deemed serious misconduct.
Humphrey was warned a repeat of this unacceptable behaviour - even it was aimed at just one person - would almost certainly result in a finding of serious misconduct and him most likely being struck off.
The police also assessed the posts under hate speech laws and decided against taking further action.
The school has been granted name suppression.