But it's not Rule 15.
It's the one I posted in post 3.
https://broncoshq.com/rugby-league-talk/25505-bulldogs-vs-souths.html#post2666304
10.
(a)If a player fouls an opponent who is attempting a drop goal, a penalty kick shall be awarded in front of the goal posts.
And
Dangerous contact on field goal: the rule explained
There was much confusion after lead referee Gerard Sutton handed South Sydney a penalty in front of the sticks when halfback Adam Reynolds' leg was taken out on a James Graham chargedown. Referees boss Tony Archer fronted the media post-game to explain the rule.
"If there is an unsuccessful field goal attempt, and there is an infringement on the kicker, that penalty is awarded 10 metres out from in front of the goal posts," he said.
"That's why they went to that position for the penalty. It's not where the ball bounces, which is just from a general play kick. That was the difference in it."
Whether the penalty should have been awarded or not, Archer was unwilling to say.
"It's really difficult for me to comment because the player has been placed on report for the dangerous contact, and there obviously has to be a process that has to occur in relation to that," he said.
Bulldogs v Rabbitohs: Five key points - NRL.com