`MISS Rusty` showed a lack of professional judgement, according to her chairman of governors at Calder High School, Mytholmroyd.
Robert Good said Leonora Rustamova (known as Miss Rusty to children) deserved to be sacked over her racy book Stop! Don't Read This, which featured pupils.
Mr Good is a district judge in social and health fields. He is also a former employment law consultant.
Ms Rustamova is claiming unfair dismissal and breach of contract.
Mr Good became involved in the case following her suspension.
"When I read her statements I did not recognise the school she was writing about," he told a Leeds tribunal.
"A lawless school - it did not accord with any of my knowledge of the school."
He added her description of "partying with wild boys" worried him as it seemed to describe a risk assessment in a consent arrangement.
"The central issue was around safeguarding. She did not really understand or appreciate the gravity of issues around safeguarding and parental consent."
Understanding safeguarding issues were a central part of being a teacher and a key issue for schools in passing Ofsted inspections, said Mr Good.
He described the publishing of her book on the internet as: "white water rafting instead of going swimming."
He also criticised "social concerns" about her judgement of having pupils in her care overnight without being open and transparent with the school.
Mr Good said during the disciplinary process Ms Rustamova had accepted she was wrong.
"But, she has to be responsible for the decisions she takes. We do not have confidence she would be safe in the future and that that could be addressed by training."
Earlier, vice-chairwoman of governors Jean Bradbury clashed with tribunal chairman David Burton.
She said the sacking had not necessarily destroyed her career.
"I bet it has not done her a lot of good," retorted to Burton.
Ms Rustamova, 40, of Salendine Nook, Huddersfield, was sacked in May 2009.
A verdict is expected within weeks.