She said Brown had whispered to her: "'You know (Pupil A) is a fidgeter. I think I am going to sellotape his legs to a chair for a laugh', or words to that effect.
"And I said something like 'are you sure that is a good idea? I think you should be careful and think about what you are doing'. And he said words to the effect of 'I do. I will do it quickly'."
Berno-Jones recalled Brown wrapped tape around the youngster's ankles four times and the boy appeared to be laughing. She said the "friendly" boy got on well with Brown and the teacher would often joke with him.
She recalled another incident in which "fidgeting" Pupil A's hands were briefly taped to a desk by Brown with his palms facing downwards and on another occasion she walked into the classroom to see a ball taped to the hand of a girl, Pupil B, who was "laughing".
Both, she thought, took place in the weeks before the chair taping.
Berno-Jones said the behaviour was not out of character for Brown who would "sometimes clown around".
The committee also found Brown guilty of unacceptable conduct over the desk taping but cleared him of the same charge in relation to Pupil B after he claimed that was an accident.
The school's then-head teacher Gisella Williams told the hearing Brown explained to her "he thought he was doing it for a joke at the time but accepted it was foolish".
Brown had worked at the school since September 2014 and was well-liked by both teachers and pupils, Williams added, and had shown no previous cause for concern.
The boy's father had come into school the following Monday after the chair incident, she said, and told her his son was upset and did not want to attend lessons.
Chair of the committee Steve Powell said: "The committee is satisfied by all the evidence that Mr Brown's actions were not malicious and it was not his intention to cause any harm to A, nor was the main purpose to restrain A.
"Nonetheless his actions were inappropriate."
He said the reprimand would stay on his record for two years and "marks the fact Mr Brown's behaviour was unacceptable and must not happen again".
Brown was not asked to return to the school following the initial complaint and deregistered last year.
He did not attend Thursday's hearing in Ewloe, Deeside.
