Mr Webber told the authority he felt "extremely intimidated" by his actions, as if he was trying to say "we have you where we want you now".
He complained to plant manager Kevin Casey, and said Mr Tapsell did not sterilise his knives properly between cuts.
A meeting was called between the two men about the complaint and ended with Mr Webber walking out.
Authority member Robin Arthur said Mr Tapsell's behaviour could not be described as "unreasonable treatment or bullying", and the complaint was dismissed.
On January 2013 Mr Webber got into an altercation with senior staff, following a search of employees' cars at the plant with sniffer dogs.
The authority heard that Mr Casey authorised a search of workers' vehicles as they left the carpark on January 16, 2013.
Mr Webber said he called Kaipara McGarvey, the Rangiura Branch President of the New Zealand Meat Workers Union, to ask why a union official was not present.
Mr McGarvey then called Mr Casey who did not agree that a union official had to be present, and Mr McGarvey later told him the searches were "bulls***".
When Mr Webber left the car park his car was searched. Mr McGravey soon arrived and told him he had the right to refuse the search.
Mr Casey said Mr Webber got "aggressive" and a "heated conversation" ensued.
Mr Webber admitted to making the comment "how do we know you c**** didn't plant stuff in it?".
He was also accused of telling Mr Casey to "come out on the f****** road and I'll sort you out", however this was never proven.
A disciplinary meeting was called following Mr Webber's alleged threatening behaviour and he was dismissed for serious misconduct on February 18.
Mr Webber later claimed he was unjustifiably dismissed and Mr Arthur agreed, as a proper investigation was not carried out following the incident.
AFFCO was ordered to pay Mr Webber three weeks' lost wages and $5400 in compensation. AFFCO was also liable to pay Mr Webber for overtime as stated in its collective agreement.
Ten per cent of these remedies were deducted, due to Mr Webber's contribution to the situation giving rise to his grievance.
Costs were reserved.
Neither party were immediately available for comment.