NRL match review committee coordinator Michael Buettner has outlined the reasons behind the committee's decision not to charge Storm winger Marika Koroibete and Souths forward Nathan Brown for separate incidents in Round 13.

Koroibete looked to have used his shoulder to force Panthers winger Dallin-Watene-Zelezniak into touch, but the committee didn't see the challenge as a typical shoulder charge.

"You can see Koroibete making his way across at great speed. When you look at the incident no charge was applicable," Buettner explained.

"It was a desperate tackle or bump on the Panthers winger and while there was no wrapping of the right arm by the defender on this occasion, you can see clear separation between the upper arm and the body, and the fact that he was also going in the same direction… we felt that there was an element of football in this and no charge applicable for Koroibete."

There was also plenty of focus on Nathan Brown's apparent stomp on Titans counterpart Agnatius Paasi during Gold Coast's golden point win in Perth, but the committee deemed the pressure not to be "forceful".

"One of the other key aspects here is that due to the contact area there wasn't an unacceptable risk of injury to the player on this occasion," Buettner said.

"Whilst some people might see it as being a deliberate action, we saw a careless action on the part of Brown, and a formal warning will be sent to the club in relation to this issue."

More from Buettner in this week's NRL HQ