Penrith prop Sam McKendry's suspension for touching referee Jared Maxwell in last Monday's win over the Roosters was an indirect result of him failing to heed a warning for players not to approach officials to dispute a decision if they are not captain.

McKendry, who told Wednesday night's judiciary hearing he was "talking with my hand" when he brushed against Maxwell's chest, rushed towards the referee to dispute a forward pass call that led to a try by Matt Moylan being disallowed.

The tribunal's decision to find McKendry guilty of contrary conduct after clearing Canterbury prop David Klemmer of the same charge five weeks ago has prompted criticism but there are differences between the two cases.

Klemmer was trying to get the attention of referee Ben Cummins to alert him that teammate Josh Reynolds was injured in back play and the whistleblower ran into him as he was racing towards the ruck to stop an altercation between Tim Browne and Panthers playmaker Jamie Soward from escalating.

It is believed that is why the NSW Origin prop was exonerated but McKendry changed direction and stepped towards Maxwell as the referee was heading to the 10-metre line with the shot clock running for a scrum to form within 35 seconds.

The NRL last season announced only the captain could approach the referee to question a decision and they could only do so after a try or during a stoppage for an injury.

McKendry is the fourth player charged this season for contact with a referee and Fairfax Media reported after the charge against Klemmer that the crackdown was designed to discourage players from approaching match officials if they are not captain.

While Klemmer was cleared by the judiciary, Brisbane centre James Roberts and Parramatta halfback Kieran Foran pleaded guilty but both escaped suspension as a grade one charge carries a base penalty of 125 demerit points and they received a 25 per cent reduction for their early pleas.

However, McKendry's penalty attracted a 20 per cent loading for a previous non-similar offence in the past two years and he also had 41 carryover points that resulted in a one-match ban.