The 10-metre protected zone rule will "drive people nuts" if the way it is interpreted doesn't change at season's end, North Melbourne coach Brad Scott says.

The Roos incurred three 50m penalties during his side's 37-point victory over the Suns on Sunday, with Scott left frustrated by what he called a series of unavoidable encroachments that resulted in hefty punishments.

The North Melbourne coach was particularly frustrated by a 50m penalty against defender Jamie Macmillan, who was running close to the boundary line when he was adjudged to have invaded the 10m protected area.

Speaking after the game, Scott questioned what his players were supposed to do in that circumstance and revealed that Macmillan had later joked about whether the umpire expected a hot dog from the stands on returning to the field of play.

"The idea of the rule is OK, because if someone takes a mark you need them to be able to play on quickly, particularly through the corridor," Scott said.

"If players are deliberately getting into that area and impeding the ball-carrier from playing on, then you need to penalise that.

"But when a guy is trying to get out of the protected area on the boundary side and he's told he should be out of the 10m protected area … Jamie Macmillan suggested that he maybe should've brought back a hot dog for the umpire after he's run into the crowd to get out of the protected area.

"But again, technically, was he within the 10m protected area? Yes, he was. But he's trying to get out of it.

"The umpires can only adjudicate the rules as they're instructed to, then it's up to the people who run the game to instruct them differently if necessary."

Under the letter of the law, Scott said the majority of the 50m penalties paid by umpires for encroachments into the 10m protected zone this season have been correct.

However, he urged the AFL to change the way the rule is being interpreted to avoid it from becoming even more of a problem in the future.

"I think for the frustration of everyone, yes (it's a problem)," Scott said.

"I watched footy as a fan Thursday, Friday and Saturday night and it frustrated me as a neutral observer.

"It will frustrate me even more if the umpires say that technically they were correct, because if they were technically correct then technically you missed 20 others.

"It's going to drive people nuts if something doesn't change."