The state's Court of Appeal has overturned a Supreme Court ruling that two years ago found against Jubilee Mines and awarded $1.86 million to former managing director Kim Riley.
In 2006 the Supreme Court ordered Jubilee, which has since been acquired by Xstrata, to pay Mr Riley who then successfully claimed that he sold Jubilee shares only after the company failed to inform the market about nickel drilling results.
The case centres on results generated by WMC in 1994 when it had unintentionally drilled Jubilee tenement McFarlanes Find, located north of the massive Cosmos nickel deposit, with the results displaying economic grades of nickel.
However at the time, Jubilee did not disclose that information until two years later, at which time Mr Riley had reportedly already sold 3.4 million shares at a price of some nine cents each.
Mr Riley had argued that had the information been released, he would not have sold his shares.
In the judgment delivered today, the court found that in the 2006 case, "great attention" was not directed to the identification or the interpretation of the ASX rules under which the claim was brought.
"When these issues were raised by this court during the appeal hearing, oral argument on the subject was significantly hampered by the lack of a full set of the Listing Rules applicable at the time of alleged contravention by Jubilee," the judgement reads.
Additionally, since Jubilee was a gold-focused company at the time WMC generated the nickel drill results, the court today found that Jubilee had not breached its duties to notify the market.
Mr Riley has 28 days to appeal today's judgement.
