"(It) may eventually involve not only RA's Code of Conduct but also aspects of contract law, Anti-Discrimination laws and employee rights under the Fair Work Act," said Carabetta.
"The case may well have a very long way to run."
Folau, 30, was issued with a "high-level" breach notice last month for taking to Instagram to proclaim "hell awaits drunks, homosexuals, adulterers, liars, fornicators, thieves, atheists and idolators" unless they repent and turn to Jesus.
The three-times John Eales Medallist had been warned last year following a similar post claiming gays were destined for hell, before signing a rich contract extension to remain in Australian rugby until the end of 2022 — but that deal that is now in jeopardy.
Last year, Rugby Australia issued a warning but no punishment. In April, Rugby Australia chief executive Raelene Castle wasn't as forgiving.
Castle said while Folau was entitled to his religious beliefs, "the way in which he has expressed these beliefs is inconsistent with the values of the sport. We want to make it clear that he does not speak for the game with his recent social media posts.
"Israel has failed to understand … that he cannot share material on social media that condemns, vilifies or discriminates against people on the basis of their sexuality."
Folau and his barrister Adam Casselden will argue that RA did not include a specific social media clause in his new contract and that his posts were merely passages from the Bible and not directly his words.
RA, to be represented by Justin Gleeson SC, is expected to argue that, regardless of no such apparent clause, Folau seriously breached the governing body's broader code of conduct policy and its inclusion policy.
Point 1.3 of the players' code of conduct policy says: "Treat everyone equally, fairly and with dignity regardless of gender or gender identity, sexual orientation, ethnicity, cultural or religious background, age or disability. Any form of bullying, harassment or discrimination has no place in rugby."
Another section states: "Do not use social media as a means to breach any of the expectations and requirements of you as a player."
Folau's defence is also expected to argue that rugby's "inclusion for all" policy should include him too — and his strong religious beliefs.
If the tribunal determines that Folau has in fact breached his contract, the panel must then decide if the breach was severe enough to terminate his career. The losing party will have until 72 hours after any decision is handed down to appeal.
And even after that, the matter could well drag on in the courts.
"There may be some kind of settlement between the parties," Carabetta told AAP. "But if it does end up in the ordinary courts such as the federal court, potentially, those matters can take months or even a couple of years."
