By now, many of those who work with Roy Keane in TV - and like him - know how to wind him up. It will often be as simple as just saying a name.
"What do you think of him, Roy?" Keane will sometimes just purse his lips, give a look, but then a quick dismissal.
"Come on . . . he's a clown."
There are other times he'll follow with a full destruction. The point is that, no matter the context, Keane can't mask his feelings. The anger isn't an "act", as many have argued. Anyone saying that should perhaps familiarise themselves with the previous three decades of Keane.
Much of that time also points to a genuinely personal angle to this. Ole Gunnar Solskjaer is one of the few former players that Keane counts as a friend. The Norwegian calls him for counsel. They've had long discussions in each other's houses.
It's why, Keane being Keane, he would genuinely have been enraged by the thought of players letting his mate down. That is doubtless where so much of his rage about Harry Maguire and David De Gea came from, a rage built on his ongoing irritation with "the modern player".
Keane has variously described them as "too soft", "very weak human beings" and lamented "you cannot say a word to them".
This outburst is probably the culmination of that thought process. It really isn't difficult to imagine Keane texting Solskjaer and telling him he needs to tell these players what's what. This may well have been Keane doing it for him, in a way Solskjaer can't.
That very notion feeds into a wider debate about what modern management and modern punditry are.
Those familiar with the modern Sky Sports say they'd "have been loving" Friday. "They got their clicks and viral videos."
There is always the danger that, if you start prizing that, you begin to aim for it over the informed natural discussion that instead produces it naturally.
Keane's emotional rant was certainly different to the more analytical approaches that have gone viral from Gary Neville and Jamie Carragher in the past. All punditry should be impassioned, because it's that love for the game that makes it go deeper.
The actual football opinions here felt rather shallow. Keane wasn't telling us what Maguire should have done, or how he'd expected De Gea to have gone for Steven Bergwijn's shot. He was simply berating them.
That has led to a lot of commentary that, in the space of two minutes, Keane showed us why he hasn't had a manager's job in nine years.
But there's much more to it than that. The argument is now well-worn that the modern manager can no longer belittle players into better performances, which is why Solskjaer could never have said what Keane did. They just don't respond to that any more.
But what is there to respond to?
It sometimes feels as if as much of the problem is articulation, as if Keane can't fully communicate what he inherently knows from so long in the game.
That's a pity, because there's evidently a wealth of knowledge there.
And it's obviously easier to impart that knowledge when you're a player alongside them, literally showing them what to do.
Keane, so clearly, understands the rhythm and intricacies of the elite game at an innate level.
The real difference with the top managers and pundits, though, is how clearly they communicate this.
This is the great irony of his rant.
In making his point so forcefully, he didn't really make his points at all. All the attention was on the anger, rather than the source of the anger.
De Gea has now been making big errors for well over two years, going right back before the 2018 World Cup. There are big questions there.
Maguire has weaknesses that can be exploited a bit too quickly, for an £85m defender.
These are issues that Solskjaer is going to have to sort if United are ever to be champions again under him. The problem, after all that, is that Keane didn't express himself enough.