You might think this sort of behaviour is typical in the world of UFC, described as "human cockfighting" by the father of Las Vegas casino bosses Lorenzo and Frank Fertitta III who bought the tiny business in 2001 — and sold it fifteen years later in what was the most expensive sporting sale in history at $US3.77 billion.
But when UFC vice president of athlete development Reed Harris, who was on the bus, tweeted, "we thought we were gonna die", you know this time was, indeed, "different".
"I've been in dozens of scuffles in UFC. Never once was I scared," wrote Harris, in a since-deleted tweet.
"This time was different".
Just 24 hours earlier, UFC president Dana White had shut down questions about shutting McGregor out of the event, telling media "it would be awesome if Conor McGregor was here".
"This is a fight that is very important to him and his future," White said.
"I don't think he has any plans to be here, I don't know where they got that information from."
It's not the first battle between the UFC president and McGregor, though. In 2016 White pulled McGregor from his UFC 200 main event after McGregor informed UFC officials that he would not participate in any press or promotional activities, including a commercial shoot and press conferences.
Earlier this week reports indicate McGregor was "on the fence" over travelling to New York, however the decision to defend his mate Artem Lobov, who was also involved in the Barclays Centre altercation, set the retaliation wheels in motion.
Lobov and fighter Khabib Nurmagomedov clashed horns in an ugly hotel lobby altercation just days prior. The incident reportedly sparked the McGregor-led attack.
McGregor quickly established himself as one of the UFC's most talked-about stars after signing up in early 2013 with his sharp tongue and overflowing confidence, but over the years his bravado has become noticably more bullish.
Just hours before his latest outburst, McGregor had taken to Twitter with a feisty message: "You's'll strip me of nothing you's do nothing c**ts."
It appears the superstar was more than a little perlexed at the thought of losing his lightweight title, after a decision by the UFC to strip him of the belt because he has yet to defend it. The title would be awarded to the winner of Saturday's fight between Khabib Nurmagomedov and Max Holloway in New York.
So what happened to the business's most bankable star?
"I don't know if [McGregor is] on drugs, or what his deal is. But to come and do this and to act like this — you're talking about a guy who had a baby," White added.
"He just had a kid. This is how you're acting? You have a son at home."
McGregor was once the proud title owner of both the 145 and 155-pound championships and even boldly stated he wanted an ownership stake in UFC.
But after a string of public incidents the trash-talking 29-year-old has been out of the octagon, except for his big boxing bout with Floyd Mayweather eight months ago that made him wealthy enough to never have to fight again after pocketing $30 million.
Prior to the incident, White had said McGregor would "100 per cent" return to UFC in 2018, but things have taken a darker turn.
"I guess cocaine really is a hell of a drug," tweeted UFC welterweight champion Colby Covington, who also chose to refer to McGergor as a "coked up leprechaun".
In hindsight this latest incident was no surprise from a man who has been criticised too many times for "finally going too far", including his comments on the monarchy (he said "Fuck the Queen" in 2015) and his "lapse in judgment" after calling Russian-born German fighter Dennis Siver a "Nazi" and demanding he "kiss my feet" in 2014.
McGregor deleted the tweet and posted afterwards: "Ich bin ein sowwy. Now about them feet ..."
"There's a line between trash-talking and inappropriate behaviour, and McGregor triple-jumped it," wrote the Bleacher Report 's Hunter Homistek at the time.
"It shows that he's not genuinely sorry, merely offering a half-hearted apology to keep the masses off his back.
"That shouldn't work for him. He shouldn't receive a pass just because he's Conor McGregor, and the UFC will undoubtedly need to sit down with its favourite Irish superstar and have a nice chat about social media (and human being) guidelines.
"He's clearly forgotten them somewhere along the way."
This all sounds like history repeating. Months later he was criticised for his comments surrounding Brazilian fighter Jose Aldo: "I own this town, I own Rio de Janeiro," McGregor said.
"In previous times I would invade his favela on horseback and would kill anyone who wasn't fit to work, but we're in a new time, so I'll whoop his ass instead."
It's also not the first time he has been in trouble for throwings. Months after his Rio comments he hurled cans of energy drink in a heated stoush at fighting duo the Diaz brothers.
He was subsequently fined $25,000 by the Nevada State Athletic Commission and handed 25 hours community service.
McGregor pleaded with fans in February that "I am fighting again. Period. I am the best at this" and asked fans to "respect the insane amount of work outside the fight game that I have put in. On top of the fighting. I am here. It is on them to come and get me."
What this latest rampage means for his future is at this stage unclear, although White said he expects the star to "be sued beyond belief".
"Everyone's shaken up. This is the most disgusting thing that has ever happened in the history of the company," he said.
"I think after this disgusting, despicable move, I think everyone's relationship with Conor's not going to be so great."
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