Mr Addis, who has visited far-flung corners of the world including China, Indonesia, Russia and India, was allegedly confronted by Mr Lewis who refused to accept he had a valid ticket on a journey to Prestwick Airport. Mr Addis, 24, said he had been left feeling "more like a criminal than a customer" by the "aggressive" encounter.
He said he never wanted Mr Lewis to lose his job and the RMT was wrong to strike.
He added: "This is purely an issue about customer service, it shouldn't have to affect the general public. I'm absolutely gutted to hear it's going to affect people over Christmas. Passengers shouldn't have to face difficulties like this."
The incident that sparked the forthcoming strike took place in March, when Mr Addis was travelling from Gourock for a holiday to Crete.
He was trying to use a Ryanair promotion that allowed him free train travel when the dispute occurred.
A ScotRail spokesman said: "The customer's comments on the incident reflect the seriousness of the situation."