Citing intellectual property abuse, Beverly Hills-based lawyer Alan S Gutman said Dr Pepper's promotion was "an unmitigated disaster which defrauded consumers and, in the eyes of vocal fans, 'ruined' the day of Chinese Democracy's release."
A trade mark attorney said that Rose may have had a strong case – but his own behaviour eight months ago appears to have weakened it.
The high-profile album was the subject of numerous missed deadlines over several years. These repeated delays became the subject of a Dr Pepper press release in March.
"In an unprecedented show of solidarity with Axl, everyone in America, except estranged GNR guitarists Slash and Buckethead, will receive a free can of Dr Pepper if the album ships some time – anytime! – in 2008," it said.
The release made a joke of the album's high-profile delays, pointing out that the soft drink shared Rose's quest for perfection. "We know once it's released, people will refer to it as 'Dr Pepper for the ears' because it will be such a refreshing blend of rich, bold sounds – an instant classic," said the release.
When it became clear that Chinese Democracy would be released in 2008, Dr Pepper said it would honour its promise. However, in what Gutman called "a cynical attempt to mitigate its exposure," Dr Pepper restricted the offer to a 24-hour window. Americans had to visit drpepper.com on Sunday, the day of the album's release, to obtain a coupon that could be redeemed for a free drink.
The rush for coupons caused the website to crash. Dr Pepper extended the deadline for another day, but some fans then complained on other sites that they had been unable to obtain a coupon.
On Tuesday, the day after the offer expired, Rose's lawyer wrote to Larry Young, CEO of Dr Pepper Snapple Group Inc.
"To begin with, our clients are outraged at your treatment of their fans and the American public in general," wrote Gutman. He described the company's failure to meet demand as "a complete fiasco".
He accused the drinks company of a "raw and damaging commercial exploitation of our clients' rights" and said that consumers had been misled into thinking that there was a "copromotional relationship" between the parties. "This association is even more damaging in light of your shoddy execution of your disingenuous giveaway offer," he wrote.
However, the letter from Gutman does not mention that his client appeared to respond to Dr Pepper's initial announcement. A statement appeared on the official Guns N' Roses website two days after the original Dr Pepper press release was issued.
Attributed to Axl Rose, it said: "We are surprised and very happy to have the support of Dr. Pepper with our album Chinese Democracy as for us this came totally out of the blue. If there is any involvement with this promotion by our record company or others we are unaware of such at this time. And as some of Buckethead's performances are on our album I'll share my Dr. Pepper with him."
Jude Tonner, a trade mark attorney with Pinsent Masons, the law firm behind OUT-LAW.COM, said that if this was a UK case, Rose's statement in March could undermine his own case.
"If Rose had stayed silent, he probably had a good case over the unauthorised press release. It's probably a trade mark use and so in the UK there would be an argument of both trade mark infringement and passing off," said Tonner. "We've seen cases like this before, notably when TalkSport used an image of Eddie Irvine without permission."
In 2003, racing driver Eddie Irvine won damages from radio station TalkSport Radio after it used his image in an advert without his permission.
"As a consequence of what appeared on the band's website, Dr Pepper will surely argue that Axl was happy and had given his permission," said Tonner. "It implies that he consents to the use. However, under UK law, the onus would be on Dr Pepper to prove this."
Earlier this year, rapper 50 Cent sued fast-food chain Taco Bell in the US after it invited him to change his name in a letter sent to newspapers.
"For one day this summer, change your name either 79 Cent, 89 Cent or 99 Cent by showing up to one of our more than 5,600 locations nationwide and rapping your order in the drive thru with your new moniker," it said.
50 Cent argued that Taco Bell used his image and trade marks to promote itself without his permission.
Tonner said that Rose's case might be limited to any detriment caused to the Guns N' Roses brand as a consequence of fans' ill-feeling towards the promotion.
Gutman's letter demands full-page apologies in national newspapers, an extended offer to consumers and "an appropriate payment" to Rose and the band.