The tribunal was told Smyth asked Nankervis if he could start work a month later so he could go to a wedding in India. But the request was denied.
On June 8, Smyth, who suffers depression and bipolar, provided two sick certificates covering June 8 to July 18, 2016.
"The period for the second certificate was for the same period Smyth had sought and been denied annual leave," tribunal commissioner Paul McMahon said.
"During this period of time off, Alwyndor became aware of Facebook posts that indicated Mr Smyth was in India attending the marriage of a relative of his wife."
Alwyndor accused Smyth of misleading them about the reason for his absence and sought an explanation but the employee refused to answer any questions. He was then sacked.
The tribunal was told that Smyth had a sick certificate for the two days of his daughter's baptism in January 2016, which also followed an unsuccessful leave request.
Smyth said the tickets to India were bought on May 7 and he thought it was a coincidence that his doctor provided him with the same time off.
He said he was given an opportunity to explain himself at the meeting with HR but refused.
Smyth's doctor also gave evidence, saying he provided the sick certificates because he believed his patient was depressed after his release from jail.
Alwyndor's then-general manager Travis Hill told the tribunal that he believed Smyth had exaggerated his illness to the doctor to go to India.
He said Smyth was arrogant in that final meeting and had a "you can't touch me" attitude.
In his decision, McMahon said there was no dispute that Smyth had a genuine illness in July 2016 but Alwyndor had reasonable grounds to suspect it was being misled.
He found Alwyndor would not have fired Smyth had he further discussed his absence with HR.
- news.com.au
