The first teacher to win a High Court appeal against the General Teaching Council (GTC) has described the "horrific" process she had to go through to clear her name.
Patricia Davies has been unable to work for three years while waiting to fight her case in the High Court.
The science teacher was reprimanded last year after being accused of telling pupils a presentation by the National Blood Service was "boring".
Colleagues also said she ignored a child who was lying on the floor, crying and holding her leg.
But in February a judge ordered the case to be heard again and she has just been found not guilty.
Miss Davies, who was assistant head of science at Willingsworth High in Tipton, West Midlands, fought her battle with the support of a friend.
She has accused the GTC of using "shaky" evidence and plans to make a formal complaint against it.
Miss Davies, who is also fighting a separate unfair dismissal case against the school, said she asked questions to make the presentation by the blood service "more interesting". She also denied not attending to the injured child.
"I'm pleased to have won my case. I've not been able to work since 2007 and I have no money, so my ultimate goal is to return to teaching. This has been a horrific process," Miss Davies told The TES.
"I've had to use my savings, I've been suffering from stress and depression and I've had to put off scheduled operations so I can be at hearings.
"I was very upset at the stain on my record after being given a reprimand, with the case being based on errors. It has taken so long to clear my name, but if I hadn't won there would be no question that I would go through this again.
"The evidence presented to the GTC was conflicting, and some statements were unsigned; there were material errors of fact.
"I feel let down by the GTC; I don't think they are impartial."
A year ago the GTC panel said her behaviour had fallen short of that expected of a teacher and she failed "to observe basic standards of professional courtesy".
They said her behaviour was "totally unacceptable".
But the same panel made a U-turn last week, concluding that her behaviour had not involved a "breach" of any standards.
Miss Davies had made the remarks about the blood service while its representatives were present.
They told the GTC that in three years of giving talks to schools they had never been so "disgusted" by their treatment.
Judge Hickinbottom, at a case heard in Birmingham in February, said this charge should be dismissed. The new GTC case heard only the allegation that Miss Davies had not attended to the hurt child.
A teacher said Miss Davies was writing detention slips instead of attending to the pupil.
The girl said she had been pushed over, and while on the floor stools had been thrown or kicked at her leg. But Miss Davies says she helped her up and called first-aiders.
The GTC panel at the new hearing defended Miss Davies' actions.
"This was a single episode where children were misbehaving in a busy classroom and Miss Davies had a number of competing demands on her attention," they said.
"These circumstances are bound to occur from time to time in a school.
"Although Miss Davies could have responded more effectively in the circumstances, the event taken on its own is not so serious as to justify a finding of unacceptable professional conduct."
The panel said she had failed to "take appropriate action", but this would only have been unacceptable professional misconduct if it was a "serious or repeated breach".
Miss Davies hopes to return to work at the school, which is now an academy, but was waiting until her GTC case finished to start looking for jobs. Her employment tribunal case will be heard in July.
SIX WHO TOOK ON GTC
Since April 2008 six teachers have appealed against GTC decisions, taking their cases to the High Court.
Three of the appeals were dismissed, one withdrawn and one - Miss Davies' - was dismissed in part.
"The GTC does not comment on the detail of any cases as only the hearing committee is in a position to consider all the evidence presented," a spokeswoman said.
"Each committee is advised by an independent legal adviser and sits as an independent and impartial tribunal. However rarely used, the GTC strongly supports the existence of an appeal route as an important mechanism for scrutinising and safeguarding the integrity of its processes."