Umm onfield punishment has always reduced the punishment
Dismissed Players
41A. (1) Subject to sub-Rule (2), in any case where:
(a) A Player has been dismissed from the field of play during the course of a Match (other than a Pre-Season Trial Match) in the NRL Competition or the National Youth Competition; and
(b) The Player is charged with an offence or offences arising out of the incident in relation to which he was dismissed; and
(c) The Player subsequently pleads guilty or is found guilty of that offence or offences;
then, in order to reflect the period during which the Player was absent from the field of play in consequence of his dismissal, the Player shall be entitled to a reduction in the demerit points that would otherwise have been allocated to him, which reduction shall be equivalent to the number of whole minutes the Player was absent from the field of play.
https://www.qrl.com.au/siteassets/d...e-of-procedure-2017---final---qrl-edition.pdf
So maybe the MRC has taken this into account.