Quins, veggies and capital punishment
The 22-26 reverse from a position of authority leaves Quins rock bottom in a season which has already seen the club warned by the Rugby Football League about their attendances ahead of the renewal of Super League licences in a couple of years.
Mac was due to join myself and Gabby Logan on our Monday lunchtime Radio 5 Live Sports Panel.
With rumours rife on internet forums and local radio phone-ins the previous evening that he had quit his job, McDermott quite rightly opted to spend the day with the players rather than the media.
"The weekend hurt Brian a lot, he took it very personally," influential half-back Luke Dorn told me as we caught up for a chat this week.
I shared a few beers with Dorny on a lively night out in Edinburgh at last year's Murrayfield Magic and we stay in touch.
Coach McDermott has had plenty on his mind so far this season
Indeed Dorn himself was keen to step into Mac's shoes on our 5 Live show before David Beckham usurped him by snapping his Achilles. "I can't believe you've brushed me for Becks!" he said. "Since when has David Beckham been more important than me?!"
The entertaining Aussie calls himself a Londoner now and lives and breathes Quins RL.
He also has the frustration of not being able to do a thing about their current predicament, as he recovers from shoulder surgery.
Captain Rob Purdham's been out with a shoulder injury too and the experienced pair have left a gaping void at The Stoop, but both are close to returning.
"Purdo is a couple of weeks ahead of me, he'll be back playing in two or three weeks," says Dorn. Both he and Purdham were present when McDermott got his troops in for a crunch chat after that Salford setback.
"He sat us all down on Monday and told us we are good players, and assured us things would improve. In particular he told us we have to be smarter and work harder for each other. That's the way Mac works - it is about hard work and digging yourself out of the hole.
"He didn't even mention the rumours about him quitting that sprung up from somewhere on Sunday night. I don't even know if any of the players had heard anything.
"I only learned on Tuesday that there was speculation Mac had resigned. This never came up in our Monday meeting so Mac clearly didn't think it was enough of an issue. It was never spoken about."
McDermott is not a quitter, and his desire to see and encourage his players on Monday rather than conduct a media interview underlines that.
But he badly needs a response from his squad, and the sooner he gets the guile and leadership of Dorn and Purdham back the better.
Not only to make things click off the field, but also because the pair are starting to do each others' heads in off it!
"We're the best of mates at the moment," says Dorn. "All we do is hang out with each other so we're well and truly sick of each other at the moment.
"The days are long as we want to be involved in the weights sessions as much as possible so we do our own rehab and then do the sessions with the rest of the squad.
"But I do find a bit of Playstation time in the evenings. I can't play Purdo as he has no idea what a Playstation is!.
"Purdo's not even got a computer and would rather go and clean his potatoes in the back yard! He has a proper little vegetable patch down the bottom of his garden."
So that's one positive at least from Quins' disappointing season to date. Their captain has used his injury lay-off to fine-tune his outstanding organic veggies!
"He's from a farming background so he's pretty good at it, and very proud and massively protective of his vegetables," says Dorn.
Purdham has spent more time pulling up weeds than pulling down opponents this year
"Whenever he invites the boys around, it normally means there is some digging in the garden that he needs help with."
Purdham's potatoes may be thriving, yet on the pitch Dorn is adamant that the players are not turnips.
"The mood is a little bit flat but we are confident we can snap out of this and we have to be. We lost the Salford game because we didn't take our chances and our kicking game was a bit off once again," he said.
"We just have to sort a few little things out, and we will be more competitive, the wins will start ticking over and things will start getting better."
Having been missing all season after dislocating his shoulder in training, Dorn has seen first-hand just how much his coach lives and breathes rugby league in the capital.
McDermott arrived in London four years ago as a Yorkshireman looking to spread the gospel of our great game on relatively alien soil. Two years later, on a much smaller scale, I made a similar move from Leeds.
Yet whereas my main challenges are convincing producers that rugby league stories are worthy of inclusion on 5 Live, and convincing landlords to whack the rugby on the big screen in west London pubs on a Friday night, McDermott shoulders the responsibility of making the sport a success in the capital.
"I sat up next to Mac in the stands during that Salford game and we were talking things through in the first half and were confident we were getting on top, and were in control," said Dorn.
"Then we lost the lead, things started to slip and I could tell how much things were beginning to get to Mac. Sitting up there for the last five games next to him I have seen all his moods and this is the most disappointed I have ever seen him. "
As one of the senior heads in the squad, Dorn also acknowledges and understands there is arguably more importance attached to the success of Quins than any other side,
"There is a bit more pressure on Quins as a team as we realise how important it is for the sport to have a successful London team and that's always at the back of our minds," he admits.
"We definitely feel the pressure of the bigger picture and we have the burden of trying to make London a successful team. We need the crowds and money coming in.
"You can talk about marketing the game down south but the best way of doing it is to have a successful team and that is our responsibility. If we can't become a successful, watchable team, then why should people come and watch us? "
Elsewhere I can't wait to see Gareth Thomas make his rugby league debut for Crusaders.
The veteran is in great shape but I expected the Welshman would be used at centre.
Brian Noble tells me Thomas will play on the wing. He told me his training has been "real good" and he will be "great" as a rugby league player.
I've been sharing a bit of banter with Thomas on twitter this week and to say he has taken to the warmth and friendliness of rugby league would be an understatement. I hope he is a huge success.