The Employment Court judgment in the most recent case said compliance problems continued, and several disciplinary issues were raised.
The company said he had refused to obey lawful and reasonable instructions, but Mr Shanmuganathan said he was being bullied and subjected to unreasonable micro-management.
His refusal to take part in a self-assessment exercise during a performance review process triggered a disciplinary process, which resulted in him being demoted from his role, taking a cut in salary and apologising.
Mr Shanmuganathan took a personal grievance case over the demotion, with the Employment Relations Authority finding the decision was unjustified. However, reinstatement was not practical.
The case was reheard by the Employment Court, which agreed with the decision to reverse Mr Shanmuganathan's demotion because of "significant procedural flaws" on the part of PowerNet.
However, the court found he should be reinstated, saying it would require "careful and proscribed management". The parties were ordered to attend mediation before reinstatement conditions were ordered.
But due to Mr Shanmuganathan being to some extent "the author of his own misfortunes", the court said, no financial remedy was ordered.