The billionaire co-founder of Tim Hortons is appealing a court decision that allows a woman's sexual-assault lawsuit against him to go to trial, his lawyer said Thursday.

For one thing, lawyer Chris Kostopoulos said, the judge was mistaken to conclude Ron Joyce had tried to trick the woman into believing the matter had earlier been settled, and applied the wrong test as to whether they had struck an out-of-court deal.

"If both parties were pretending there was a settlement, then the matter is settled," Kostopoulos said.

In allowing the $7.5-million suit to proceed to a hearing on its merits, Superior Court Justice Paul Perell also struck down the woman's defamation claim against Joyce, although he tore a strip off both sides in a 40-page decision that drips with contempt about what he heard.

"An enormous amount of irrelevant evidence was hypocritical, intemperate, and rude," Perell wrote. "An enormous amount of evidence had no purpose other than character assassination of the witnesses and of the friends and family of Mr. Joyce and (the plaintiff)."

In addition, Perell went on, much of the evidence advanced at Joyce's motion in February to dismiss the suit was irrelevant, but, if true, would be "proof of serious criminal activity, including extortion, fraud, drug trafficking, obstruction of justice, and perjury."

Joyce, who painted his accuser as a "pathological extortionist," had wanted the suit thrown out on the grounds that it was launched too late. He also argued he had already paid the woman $50,000 as a final settlement of the dispute arising out of the alleged incident.

Perell rejected both those arguments, even though he found many of the woman's submissions were little more than a polemic against police, lawyers and the justice system and both accounts of what happened were emotionally distorted, irrational and unreliable.

"Much of the evidence was inflammatory and designed to enrage the court or the media since both sides are intent on winning a public relations war," Perell said.

In her statement of claim, the woman, in her mid-30s, alleges Joyce sexually assaulted her at his home in Burlington, Ont., on May 19, 2011. The pair had known each other for a decade and, for one period, had an intimate relationship.

Later that year, Joyce sent a $50,000 cheque to her lawyer on which he wrote her name and "account paid in full."

Joyce argued the cheque was the result of an amicable settlement over the alleged assault and she resumed a platonic relationship with Joyce, who's now 85. The woman, who had a penchant for secretly recording their private conversations, argued the cheque was reimbursement for her legal fees.

"Apart from concluding that both Mr. Joyce and (the woman) are vulpine and cunning, for the purposes of deciding this summary judgment motion, I need not decide who was the hunter or who was the fox," Perell said.

What Perell did decide was that the woman did file her claim within the allowed time given her mental state at the time and that there was no final settlement that precluded further litigation. Both sides, he found, were "attempting to play tricks on one another."

He said he simply disbelieved her slander claims.