Canterbury coach Trent Barrett wants to get to the bottom of what made Lachlan Lewis snap after a brain explosion spoilt Canterbury's shot at upsetting South Sydney.
In a dramatic clash, the Rabbitohs survived a massive scare to come from two points down at half-time to beat the last-placed Bulldogs.
The win did come at a cost, with Alex Johnston expected to miss a few weeks with a hamstring injury after the NRL's leading try-scorer was hurt scoring his 24th of the season.
But it would have been Lewis feeling the worst of any player at Cbus Super Stadium.
After the Bulldogs had claimed the most unlikely 12-10 lead, Lewis found himself in trouble for tackling Cody Walker as they walked from the ground.
Walker and Lewis had words as the players were exiting the arena before the Bulldogs five-eighth took his opposite number to the ground and sparked a melee.
The off-contract playmaker was then called back onto the field by referee Ben Cummins, and sin-binned for the start of the second half.
And Walker made him pay.
With Lewis off the field, he touched the ball twice in one play to put Johnston over for his second try.
Souths also booted a penalty goal in that time, with the eight points they scored while the Bulldogs were down a man ending up being the difference.
"I'd like to know what happened actually, for Lachy to react like that," Barrett said, insisting Lewis hadn't cost his team the game.
"It was completely out of character. Obviously, something's happened for him to react like that.
"It hurt us.
"I didn't know you could get 10 minutes in the sin-bin after play had been stopped and you're walking off at half-time.
"He didn't hit him or anything, but obviously something's happened."
Walker didn't elaborate when asked by Fox League after the game what had prompted the incident, only to say "what happens on the footy field stays on there".
But it was clear the drama gave Souths a massive leg up at the break.
"He (Lewis) was going to be in the bin for 10 minutes so (our players) knew it was going to help us," Souths coach Wayne Bennett said.
"We may have got the (eight points) anyway but you know with 12 men on it becomes more difficult (for Canterbury).
Lewis did gain some redemption when he set up Jayden Okunbor on return to make it 18-18, before three more South Sydney tries gave them control.
The result covered up what would have been a worrying night for Souths.
On top of Johnston's injury, Liam Knight and Campbell Graham suffered early concussions while Latrell Mitchell was rested.
The 24 points they conceded was the second-most scored by the Bulldogs all year, after Souths looked in control early before bombing more chances.
Bennett's men completed at 74 per cent and had their defence split open by Bailey Biondi-Odo from dummy-half in the first half.
Souths also gifted the Dogs rookie a try in the second from a spilt ball to give Canterbury a faint hope at 28-14, before Mark Nicholls closed the game out.