England and Saracens forward Vunipola took to social media on Friday to defend his decision to "like" Folau's post and also backed the Australian over his comments.
Vunipola has liked Folau's post and states on his own account that "Man was made for woman to procreate that was the goal no?, though he went on to say: "I don't HATE anyone".
The Australian's Wayne Smith reports Folau and his management privately believe RA's handling of his dismissal may not stand up in court.
England's star back-rower Billy Vunipola could face sanctions after he appeared to back an Instagram post published by Israel Folau in which the Wallabies full-back made homophobic remarks.
Mark Fowler, an adjunct associate professor of law the University of Notre Dame, told The Sydney Morning Herald that RA would have to prove they were not terminating Folau's contract because of his religion.
Rugby Australia stated they would be keeping the details of their discussion private and will update their respective Boards to consider next steps.
If Folau successfully sued Rugby Australia for the millions of dollars remaining on his contract, it would be a serious blow for the already financially-stretched organisation.More news: Why Meghan Markle's Baby Plans Are Not a Reflection on Kate's
More news: Army of lawyers prepares for Assange extradition battle
More news: Trump signs measures easing energy regulation while in Texas
Folau took to Instagram to proclaim hell awaits "drunks, homosexuals, adulterers, liars, fornicators, thieves, atheists and idolaters".
"Ultimately these are matters for Australia, not for us, but we can hold our views on what he's said".
"It is important to note that Israel remains contracted to both Rugby Australia and the NSW Waratahs at this time, and as such has signalled his intention to continue to honour his contract", RUPA said.
"RUPA does not endorse or condone the content of the social media post made by Israel Folau on Wednesday night, however it is imperative that the proper process is followed under the Code of Conduct", the statement read.
Folau had just last week become Super Rugby's all-time leading try scorer, and if terminated, he would be unable to complete the season with the Waratahs or play for the Wallabies at the Rugby World Cup.
"Some of the comments which have been seen are far closer to hateful than I think appropriate for what people should be doing on social media".
"Guys are always trying to promote the game as well as we can".
If this truly is the end of the road for Israel Folau in Australian rugby, his auto crash-style exit will have been as swift and spectacular as his rise was meteoric.