Stewart Walker was sacked after the occurrence in Broughty Ferry in 2015 when he was alleged to have lost mail, fell short to safeguard his work van and failed to report the missing mail quickly.
Mr Walker claimed he had been granted ₤ 37,000 but this figure has actually been minimized to ₤ 18,500 because of the Royal Mail’s “contributory conduct” judgment.
“We note that the tribunal has actually not bought Royal Mail to restore Mr Walker, in spite of this being the remedy he looked for, due to the fact that the tribunal figured out that it was not possible for Royal Mail to do so, provided that he had actually confessed to a rather severe breach of discipline.
However, the company refused to accept the ruling and appealed the decision.
Mr Walker said he had been awarded £37,000 but this figure has been reduced to £18,500 because of the Royal Mail’s “contributory conduct” ruling.
He said: “I have been discussing with my solicitor whether or not to accept this figure.
“I believe I am entitled to several thousands more because I have lost holiday pay and I am not being given money for the Royal Mail shares I held.”
Tribunal judge Lady Wise rejected the appeal but reduced Mr Walker’s backdated holiday pay entitlement almost five-fold from £1,054.99 to £218.27.
Mr Walker added that he had always intended to donate £1,054 holiday pay to the special care baby unit.
He said: “Even although that has been reduced by the judge to £218 I still intend to donate the bigger amount to the unit.
“I will just now pay this out of my own money.
“While I respect the decision of the industrial tribunal I am upset at the devastation this has caused in my life.
“At no time did I do anything with any criminal intent. The only mistake I made was to not report this bag missing as soon as I discovered it was.”
Mr Walker, 40, of Tealing, was sacked after the mailbag was found in the street and handed in to nearby Barnhill Post Office by a resident.
He initially thought he had been alone in the van when the bag was lost and took responsibility.
But when he was told where the bag had been found, he realised a colleague had been with him at that time and may have been responsible for the loss.
However, Mr Walker was suspended and later sacked for gross misconduct while his colleague kept his job.
Mr Walker continued: “This has proved to be very stressful for me over the past two years. I had a clean record with Royal Mail for more than 20 years.
“This has had a completely devastating effect on me.
“I have been forced to retrain at my own expense. I’m not happy with what I am being offered.
“I have lost savings. My pension has been affected and I am concerned I have lost shares worth thousands of pounds.”
The matter will now go to a remedy hearing to determine the amount Royal Mail must pay in compensation.
Ryan Russell, a partner in Muir Myles Laverty Solicitors, said: “This judgment is final vindication of Mr Walker’s case and full and final proof that Royal Mail acted wrongly in dismissing Mr Walker.
“We believe they acted unnecessarily in dismissing him in the first place and again by appealing the proper judgment of the employment tribunal.”
A Royal Mail spokeswoman said: “Royal Mail is disappointed with the tribunal’s decision in this case. Royal Mail will continue to treat cases of alleged misconduct extremely seriously and take action accordingly.
“We note that the tribunal has not ordered Royal Mail to reinstate Mr Walker, despite this being the remedy he sought, because the tribunal determined that it was not practicable for Royal Mail to do so, given that he had admitted to a fairly serious breach of discipline.
“Due to this admission, any award made to Mr Walker will be subject to a reduction of 50% as a result of his contributory conduct.”