Referee Ashley Klein's oversight in allowing play to continue for almost 50 seconds — after Keppie went in for a tackle on the Rabbitohs' Mark Nicholls but caught a hip to the head — was a flashpoint for player safety.
A similar incident later that weekend involving Melbourne's Christian Welch, who like Keppie failed a HIA when eventually taken from the field, led the NRL to overhaul its head injury policy.
An independent medical doctor, operating from the remote NRL Bunker, will have the power to immediately rule a player out of a match if they show category one symptoms like unsteadiness, not properly bracing for a fall or loss of consciousness.
While concussion spotters have been stationed in the Bunker, the ultimate decision to replace a player and conduct a HIA had rested with club-employed doctors.
"It was pretty horrific to see what happened," Keppie told AAP of his concussion, after which he fell to the ground before attempting a tackle to deny a Souths try.
"That new rule will definitely help players in my case where the ref didn't stop the game straight away and potentially (the opposition) could have scored a try or made my head even worse."
Fellow Sea Eagles front-rower Martin Taupau also backed the revamped protocols, having endured his own issues after a concussion in 2020.
Taupau sought a CT scan to ensure he didn't have a brain bleed after a tackle by then-Warriors loan player Jack Hetherington left him with short-term memory loss and headaches.
He swears by a carnivore diet which he believes lessens "brain fog" among other benefits.
"In the last couple of years, you've had a lot of great players retire due to concussions," Taupau told AAP.
"It's a great move to have an independent medical person now to step in and assist in that respect."
Club trainers will also wear microphones enabling them to talk with doctors on the sidelines as they perform on-field medical assessments, something for which Manly coach Des Hasler has advocated.
The independent concussion doctor, meanwhile, will be in place this weekend as the NRLW season begins.
Keppie admitted there was a growing concern in the NRL about head knocks.
The 23-year-old was hurt in the first half of Manly's trial win over Wests Tigers last Friday after a whack to the throat but said he was fine aside from some swelling.
