The obvious response to North Melbourne's interchange bench blunder at Marvel Stadium on Saturday was incredulity, some sort of crack about not being able to count, probably both.
About the only people who might not have reacted too harshly were anyone who has spent time on an AFL interchange bench over the last 10 years or so. Indeed, they might instead have wondered how it hasn't happened more often.
I did the "boundary rider" role on radio for a good 20 years, sitting directly behind those benches, and at times the chaos down there has to be seen to be believed. Flinders Street station at 5pm has nothing on two AFL teams simultaneously making four interchanges at once.
When I first started doing the boundary gig in 2000, a major part of it was relaying on air every interchange made. It sounds ridiculous now, but as late as 2006, the average number of interchanges per game was 46.5. By 2013, that number had trebled to 133.3, prompting the introduction of the rotation cap.
Watch the footage of the North Melbourne incident and the mess-up becomes easier to understand, with Roos players Liam Shiels and Will Phillips both coming off the ground at the same time.
In 2008, I covered the North Melbourne-Sydney game (how's that for coincidence, hey?) at the same ground in which the Swans had a 19th man on the field for a minute, during which they scored a critical point in a game which ended as a draw.
A few weeks after that, the AFL introduced a rule allowing the interchange steward to inform the umpires of interchange errors. That's what brought the Roos undone on Saturday, perhaps another reason for North to be cursing the Swans.
Did the punishment of a free kick and 50-metre penalty, effectively gifting Sydney's Hayden McLean the winning goal, fit the crime? Like most, I'd argue probably yes.
After all, what's the point in having an interchange cap if the penalty for breaking it is negligible? Were the sanction merely some sort of fine or warning, clubs would be looser than ever in making sure they didn't go over the limit.
But if you're going to have draconian on-field penalties for particular infringements, there has to also be pretty rigid consistency. Which right now, doesn't appear to be the case.
The most obvious example of this is with the 6-6-6 rule, which is now in its fifth season of operation. For unknown reasons, the transgression of this rule still means only a warning for a team on the first breach before a free kick is paid the second time.
It's been said for a while already, but surely now in light of the game-costing penalty North Melbourne paid on Saturday for the interchange error, not being able to momentarily assemble six players in a zone for an impending centre bounce has to be worthy of an immediate free kick?
The potential for a team to get away with having, say, a spare defender behind the ball, as used to happen routinely prior to the 6-6-6 rule, seems of a lot more consequence than a team being allowed a 76th rotation as opposed to its opponent's 75. And after four years of being able to master getting it right?
Ditto some of the 50-metre penalties we see in today's game. I'm a big fan of the "stand" rule. I think in conjunction with 6-6-6, it's had a noticeable impact in helping open the game up to a more free-flowing and at least marginally higher-scoring affair.
But it has been a major change to how players police the mark, and even come this third year of its existence, is asking players to stay absolutely static, going against bodily instinct and what nearly all of them were trained to do when on the mark as they learned the game growing up.
Likewise, the "protected area" infringements are sometimes mystifying, players penalised when running in a pattern or to an area which has no impact whatsoever on the player in possession of the ball.
Players have to effectively learn how to run away from the football so as not to transgress, because a 50-penalty is more often than not also a shot at goal. Personally, I'd rather that was time they were spending on goalkicking practice, given some of the appalling conversion we're seeing in the game at the moment.
Is the 50-metre penalty applicable for all transgressions? I think the above is reasonable evidence it's instead often akin to cracking a walnut with a sledgehammer.
The AFL and umpires would argue that the moment you cut any sort of slack it will be exploited by clubs and coaches. But there should be a happy medium, and in my view, the 25-metre penalty the SANFL has in addition to the 50-metre penalty for more serious breaches of the rules is it.
You'd hope that the drastic consequences of North Melbourne's interchange accounting error may at least spark some rethinking of other on-field penalties, standardising them for consistency's sake.
Indeed, the Roos might inadvertently have played some role in the game getting it all in line. Just don't ask justifiably filthy North fans to take that as some sort of comfort this week.