On an embarrassing day for the Smith administration, Conlon sensationally resigned on Wednesday morning because he had "never witnessed a penalty more disproportionate to the offending conduct than that dealt out to Paul Gallen".

And the fallout from Gallen's sanctions is set to continue on Thursday, with NSWRL's George Peponis issued with a "please explain" over his relatively sedate remarks at the weekend in support of the Blues captain.

It's no secret that Conlon has been frustrated with the NRL for some time, but the tipping point has been the $50,000 fine handed out to Gallen, who last week posted on social media a message that made reference to "no other c--- from the NRL" while he was holidaying in Hawaii.

In early April, Conlon had asked Smith to take strong action over a News Corp report after Storm forward Jordan McLean was suspended for seven matches for his tackle that has left Knights back-rower Alex McKinnon in a wheelchair.

The report claimed NRL bosses had ordered the judiciary panel of Mal Cochrane, Bob Lindner and Chris McKenna to make a "grim determination" of a suspension of more than "five to 12 weeks".

Conlon was furious at the alleged attack on the judiciary's integrity. Yet his barrage of emails to Smith and chief operating officer Jim Doyle fell on "deaf ears", he claims.

"For whatever reason, the NRL was simply unconcerned in respect of this attack," Conlon wrote in his resignation letter, which Fairfax Media has obtained, to Smith on Wednesday.

"Contrast that inaction with the swift retribution by the NRL when a player tweets an expletive aimed in its direction. My role as a judge involves ensuring that punishment fits the crime. My role as judiciary chairman involves ensuring that charged players' rights are protected and that they receive a fair and just hearing. I have never witnessed a penalty more disproportionate to the offending conduct than that dealt out to Paul Gallen."

Smith and the NRL have been under enormous pressure since deciding to heavily fine Gallen for his Twitter rant following the sacking of Sharks chief executive Steve Noyce.

"Noice [sic] actually cared about players from Cronulla's feelings. Couldn't say that about any other c--- from Nrl," Gallen posted before removing it five minutes later.

Gallen has seven days to respond to the breach notice, but said earlier this week he intended to fight the $50,000 fine and the ban on him playing for Australia next year unless he sits a leadership course.

Conlon said the NRL had failed to take into the account the depression Gallen is suffering because of the ASADA investigation over the past two years and subsequent drug ban that expires at the end of this month.

"I feel I am unable to continue my role in an organisation that is so self-absorbed that [it] is devoid of empathy for those that might be struggling," he wrote to Smith.

Indeed, the saga is quickly turning on the NRL.

The NSWRL is under pressure from head office to sack Gallen as NSW captain. Peponis, who is considered one of the most respected figures in the code, has been asked to explain his support of Gallen late last week.

"At this stage it's a matter between Paul Gallen, the NRL and the Sharks," Peponis said. "Poor old Gal has been to hell and back in the last 12 months. It's inappropriate what he said [but] he feels like he didn't get a lot of support. I actually feel sorry for the bloke."

ARL Commission chairman John Grant has asked Peponis to explain those remarks at Thursday's chairman's meeting in Sydney, although it's now unerstood Peponis won't attend with the commission having already handed Gallen his reprimand.

Peponis sent a missive back over the weekend. In a letter to Grant, which has been obtained by Fairfax Media, the Bulldogs and Kangaroos legend says he will "not be drawn into an argument that has nothing to do with us at present".

"The issue of the captaincy of NSW is not something which we would or should be discussing until next year and certainly not now in the context of this matter. If this matter remains unresolved at that time, the Board would take it into consideration."

An NRL spokesman on Thursday said: "It is normal to expect that both John Grant and Dr Peponis would have regular discussions about the game and key issues as they arise – that should be unsurprising. Both Mr Grant and Dr Peponis will no doubt continue to have discussions. We thank Mr Conlon for his service to the game but will not comment on the matters raised in his letter. Paul Gallen has seven days in which to respond to the breach notice and it is appropriate that this process runs its course."