Mazza is countersuing Ornge for the money, claiming in court documents that he was supposed to receive the bonuses by February 2012 — a few days after he was terminated from Ornge amid allegations of financial irregularities.
Ornge is suing Mazza for $500,000 plus interest, saying he defaulted on a loan he received in 2010 which he used to buy a Toronto home.
It alleges Mazza tried to sell the home without Ornge's consent and "failed or refused" to repay the loan.
Mazza denies Ornge's claims, saying the $500,000 wasn't a loan but an advance on his bonuses in 2009 and 2010 that were part of his board-approved compensation package.
He admits he provided a promissory note at the time, agreeing that he would be in default if he failed to repay the loan or tried to sell the house without Ornge's consent.
But the note "was only a formality to accommodate the arrangement" that he had with Ornge for payment of his bonuses, according to his statement of defence.
Mazza didn't seek Ornge's consent to sell the home because the "requirement for such consent no longer applied" as the money wasn't a loan, the document states.
He alleges that Ornge agreed in 2010 to give him $1.3 million in bonuses when he transferred from the not-for-profit organization to Ornge Global, one of its for-profit subsidiaries that is now bankrupt.
Ornge's chairman "was concerned about the optics of making a payment of this magnitude to Mazza at that point in time," the document states.
Mazza alleges the former chairman gave him one bonus and agreed to pay two others through a housing loan.
"Mazza was assured by the chairman that he did not need to be concerned that the $500,000 payment, made to him in 2010, was described as a loan," the document states.
Mazza said his employment from Ornge Global was terminated in February 2012 because it went bankrupt. He claims that since he wasn't fired with cause, he's still entitled to his unpaid bonuses.
The legislative committee investigating Ornge has heard that Mazza received $1.4 million in compensation, on top of hefty loans totalling $1.2 million in a single year.
Ornge said bankruptcy trustees are pursuing repayment of the other loans and have recovered about $600,000 from the sale of Mazza's home.
Mazza also collected hundreds of thousands of dollars in "medical director" fees on top of his salary, the committee heard. Former members of the Ornge board have testified that they had no idea he was getting those extra fees, on top of his salary and bonus.
Ornge spokesman James MacDonald denied Mazza's allegations Thursday, but said he couldn't comment further.
Health Minister Deb Matthews, who cleaned house at Ornge after the scandal broke, also declined to comment on Mazza's claims.
"Nothing surprises me when it comes to Chris Mazza," she said.
It's unbelievable that Mazza, who is again drawing from the public purse as a hospital doctor in Thunder Bay, is suing the organization he left in tatters for $1 million, said NDP Leader Andrea Horwath.
"This has become the theatre of the absurd," she said.
"Really, you can't make this kind of stuff up. It's worse than fantasy. It's actually a horror story for Ontarians."
Progressive Conservative Frank Klees also expressed outrage.
"This man has broken the public trust, he has undermined the integrity of our air ambulance service," said Klees.
Mazza's lawyer, Roger Yachetti, did not respond Thursday to requests for comment.
Ornge, which receives $150 million a year from the government, is under a criminal probe.
Ontario's auditor general has criticized the governing Liberals for failing to oversee Ornge, despite giving it $730 million over five years and allowing it to borrow another $300 million.
The Liberals insist Ornge went rogue with a web of for-profit companies and questionable business deals, as well as exorbitant salaries and lavish expenses.