Mr Jackson raised a grievance with the Employment Relations Authority (ERA), claiming he was unjustifiably disadvantaged by TACL's decision to reschedule its services without consultation.
He also claimed his position had become redundant, and sought compensation.
But ERA member Anna Fitzgibbon found he was not unjustifiably disadvantaged because the company had consulted on the proposed changes.
The ERA heard Tramways Union delegate Haeata Paraone did not tell Mr Jackson about the proposed changes in detail because of the stress it would place on Mr Jackson, whose partner was very ill.
Ms Fitzgibbon said that was unacceptable. She also said it was unacceptable for the union delegate to fail to inform members, and then claim the company had not consulted.
She found Mr Jackson was not dismissed by the TACL.
"It is my view that Mr Jackson, in refusing to return to work and in notifying TACL of his intention not to return to work unless certain conditions which were unacceptable to TACL were met, terminated his employment."
Costs were reserved.