That night, Oasis were scheduled to play a "secret" gig at London's Royal Festival Hall for MTV's Unplugged series. Their singer failed to appear on stage, with a throat infection given as the cause. He did, however come along to watch, Patsy clinging to his side, and sat smoking in a box before tottering on to soak up the applause - but not to sing.
Then on Monday, 15 minutes before the band was due to leave Heathrow for Chicago and the start of a three-week tour, Liam called for his luggage to be taken off the plane and walked out on the group. He said he needed to go house-hunting. The official story now is that he will rejoin the tour when his throat improves next week and that in the meantime he is in London attending to "a personal matter".
I tell the tale of the Friday afternoon conversation not to make fun of any of those involved - Hopkins is an excellent PR who has done a fine job of keeping his charges in the limelight - but because it shows that the record company had nothing to do with the current controversies, and that any suggestion that all this is a put-up job for the media is untrue.
Nicknamed "the Tasmanian devil" by the rest of the band, Liam Gallagher is a 23-year-old seemingly trapped in a permanent adolescence, his tantrums and confusion part of his undeniable charisma but in danger of running out of control. Liam seems to view his band's success as a licence to do as he wishes and until recently every incident of bad behaviour - the leering over women, the partying, the confessions of house-breaking and drug-taking - only seemed to add to his appeal. Swaddled in a cagoule, hands behind his back, tambourine round his neck, Liam often hardly moves at all on stage, yet he is riveting, remaining the focus of their live shows as they have moved from small clubs to monstrous record-breaking open-air events.
Cynics say he is losing his looks while endless experts are quoted this week saying he is endangering his voice. But these may just be the gripes of die-hard fans annoyed that they now have to share their band with tabloid readers and middle-aged CD collectors as Oasis go well and truly mainstream.
For now Oasis are the great white hopes of British rock music, the only band that looks likely to replicate its massive home success in America. Whereas Blur paraded their intelligence, Oasis sold themselves on authenticity and it was a bit of rough that the rock audience wanted. When most music stars come across as corporate players, businessmen more than moody artists, Oasis give good copy. For good old-fashioned sex, drugs and rock 'n' roll they're the only show in town and they've sold well over four million albums in the UK alone as a result.
And although it's easy to forget because big brother Noel does all the interviews, Oasis were Liam Gallagher's creation. He started the band with some mates to help quell post-football boredom (both brothers are big fans of Manchester City) while Noel was off working as a guitar roadie for the Manchester band Inspiral Carpets. Noel came home in time for their debut gig and was fiercely critical. "I told our kid the band was shite but he definitely had something as a frontman. Then I said 'You either let me write the songs and we go for superstardom or else you stay here in Manchester all your lives.'"
The band opted for the former, with Noel joining and soon showing a real talent for taking elements of past hits and creating anthemic tunes that sound at once fresh and immediately familiar. Liam complains his contribution is undervalued, that the band would be nothing without him as frontman. The more conservative, music-obsessed Noel replies that his brother couldn't write lyrics, let alone hit songs, that he is disruptive, bringing mates into the studio to party while they are recording, that he doesn't turn up to rehearsals. Noel sang lead on some of the songs on their current album and has hinted that the band could continue without Liam if necessary - which is exactly what they are attempting to do for the first leg of the US tour.
Liam once said that the only things he cared about were "our Mum, John Lennon ... and being in a band". Apparently his mum Peggy loves Patsy and is keen to see the relationship work. Noel, according to people who know him, has always taken a more cynical approach, refusing to take the couple particularly seriously while privately acknowledging that the tabloids' obsession with them can only be healthy for the band's notoriety. If this is true it's just one in a long series of fights between the battling Gallagher brothers. "It's no put-on," the Oasis guitarist Bonehead once said of the fighting. "I wish it was sometimes. They've always been this way."
"Our Liam's always acted like that," his oldest brother, Paul, said in an interview with the Face last year. "He's always been, "Look at me, I'm f***ing coo-el," even before he was in a band. Us Gallaghers have always held ourselves in high esteem."
At the band's Loch Lomond gigs the weekend before Knebworth, Patsy was brought on stage to show off her engagement ring - a move even Liam's most vociferous defenders deemed irretrievably naff. On stage, Liam took to picking up the heavy mike stand and charging at his brother. Most observers thought it was just fun but those standing closer said you could see the concern in Noel's eyes as he wondered how far his brother would go. At Knebworth, Noel's obsession with the band's place in the rock canon was made clear by his on-stage declaration that "This is history!" Liam just laughed, announcing in response, "No it's not, it's just Knebworth."
Perhaps the best indication of the conflict at the centre of Oasis is an argument the brothers had during an interview John Harris, now editor of the music monthly Select. The argument has been released on CD and involved Liam contending that the band needs to cause controversy, while Noel replies that the music and the music alone, is what matters. It ends with Liam repeating the word "bollocks" while Noel replies by saying "music" over and over, an exchange worthy of bickering children, but also key to their grown-up success. Liam wants to be in the Sex Pistols while the more conservative Noel wants to be in the Beatles. It's a tension that has carried the band to their current position, but it may also be what tears it apart.
Despite Noel's belief to the contrary, it's doubtful whether the group could continue to be as big without Liam. Many of those present at the MTV show complained that Noel ruined his own songs with constant American inflections and most people agree that the band wouldn't be the same without both brothers. "People have come round to realising how important Liam is, that Oasis wouldn't be nearly as special without him," says Ashley Heath, editor of the men's fashion magazine Arena Homme Plus, which recently featured Liam on its cover. "Noel is a great songwriter, but Liam changes them from being a very good band with well crafted songs to something more than that."
Meanwhile, rumours of the band's demise are exaggerated. Whatever is going on in Liam's head at the moment - and one suspects that the shenanigans of the past few days are about more than house hunting and sore throats - he loves the applause too much to give it up just yet. As for Noel, he is too smart to ask his brother to leave just as they are on the verge of being one of the biggest bands of the Nineties in America as well as at home.
Besides, underneath it all, you suspect he loves his little brother. "We're Irish Catholic stock, so you just don't say those sorts of things," he has said in the past. Perhaps he should write a song.