A season like this deserved the perfect finale. The return of these two giants of the English game to the grand final deserved one too. Instead, we had another final this season and we had another asterisk by the result.

Three big finals; three red cards. Happily – luckily – the one in the Champions Cup final came in extra time with the initiative already seized by the team disadvantaged. Richie Arnold’s red card, slightly different from the other two in that the player, notionally at least, had a bit of time to weigh up his decision‑making, did not cost Toulouse particularly dear, or the spectacle, which had been exhilarating.

Related: Alex Mitchell try earns Northampton title as 14-man Bath are denied

But the other two … Sam Cane’s red card in the first half of the World Cup final still echoes as a hollowing-out of the game’s ultimate showcase. And now this, another red card, midway through the first half for Beno Obano for an incident measured in inches and milliseconds, leaves us wondering, fairly or not, whether the right club won.

Northampton suffer almost as much as Bath in the reckoning. No one can possibly grumble about a side who have so lit up this season emerging victorious. They have led throughout and delighted us with the inventiveness of their play. But finals are finals, important not only as showcases whose integrity must be preserved for the sport’s credibility, but also as tests of nerves for would-be champions on the highest stage.

We will not know how a straight fight between these two would have unfolded. Certainly, it cannot be said Bath would have won the match had they not played an hour with 14 players, given how close the match ended up. Red cards change the dynamic of matches and, as so often, the disadvantaged side seemed to be galvanised by it, while the other team seemed thrown.

The fact we have to have this conversation is a blight on the game. To consider the incident itself, it was a classic of its kind. Obano was not quite as bent at the waist as it is physically possible for a player to be, but why pick on him? Upright tacklers are everywhere in rugby. But he was bent at the waist. More poignantly, as so often, the ball-carrier, Juarno Augustus, clearly dips at the last split-second. And so a legal tackle becomes illegal by an inch.

World Rugby presented a seminar to the media this season when they almost apologetically pointed out how rare red cards are for illegal tackles, as if to say: “Guys, we know these reds are not ideal, but, hey, most games are unaffected.”

The pre-eminent referee of our time, Wayne Barnes, now retired, felt able to question the wisdom of sending players off who had, at worst, got their timing wrong.

It is difficult to remember any red cards in the modern era for acts that were deliberate. There was one here, which springs to mind, for a stamp in an England-Argentina game in 2017. Another was the last red card in a Premiership final. Even there, though, there was sympathy for Dylan Hartley in 2013 when he lost his cool under exceptional circumstances and may or may not have called Barnes a “fucking cheat”.

But deliberate offences designed to cause harm, either physically or reputationally, are what the ultimate sanction is supposed to be reserved for – in any sport. When they are routinely issued for what are essentially accidents, or at worst failures of technique, they lose all meaning. They simply become inevitable parts of the sport.

Worse still, they will have no effect on the great crisis facing the sport. The idea that waving red cards will magically eliminate head collisions is clearly fallacious, given we are more than seven years in since the directive became official and the cards keep coming.

Even if they did eliminate them, to imagine the game’s CTE crisis boils down to the odd smack of the head betrays a fundamental misunderstanding of the dynamic. Instead, science continues to firm up the hypothesis that it is the repetition of many, many collisions of any kind, over years and decades, that is the key input.

In that same seminar, World Rugby revealed that the typical number of head acceleration events in this year’s Six Nations, as measured by the instrumented mouthguards they are now using to monitor the toll on players’ brains, is about 1,000 a match. This final had nearly 300 tackles and countless other collisions as players pile in at ruck and maul.

These are the areas that need focus. Red cards have become accepted with a sigh, but they do not need to be. We should be talking about the game, the integrity of which should be preserved at all costs. Only then will we be sure to get the finals we deserve.