Neue Zürcher Zeitung - new article
Apparently there were a few problems in New Jersey... It's a comment, the author doesn't really quote any sources, but considering that this is no tabloid but one of the most respected newspapers in Europe, it's probably not completely imaginary what she is saying (it's actually one of the
oldest newspapers in the world, which of course doesn't automatically mean that the quality is good). It's long, so I will only translate small parts.
Stéphane seemed to be in a very good mood after press conference - but the author of the article thinks that that was rather forced happiness. She then goes on to tell the reader when and why Stéphane left Switzerland, that some people have always advised him to look for a more professional training environment etc.
[...]
With his goal the Olympic gold medal in mind Lambiel was ready to risk it. The boredom had the name "Wayne" and is in New Jersey. The Russian Viktor Petrenko, Olympic Champion in Albertville 1992, is a good guy. The ISU uses the videos of his programs back then to demonstrate the judges a perfect Triple Axel. Lambiel picked this man as his new coach. To simplify matters Lambiel moved in with the family, only 10 minutes away from the rink. The 11-year-old little daughter adopted him as her new brother. In retrospect the Valaisan tries to emphasise the positive aspects of the American suburb idyll (?). Everyone was very nice. But he calls his old coach more and more often. There are problems. Why is he supposed to do the spins the same way the American Johnny Weir, who shares the ice with him, does them? After a short time he finds out that his coach isn't really Petrenko but his mother-in-law. Galina Zmievskaya is a figure-skating-general of the old Soviet school. She apparently threatens the skaters from time to time. If the Flip isn't working there will be no dinner. Her former pupil and son-in-law doesn't make any decision without her. The last straw may very well have been what happened during the planning for the Grand Prix in France (scheduled for mid-november). Zmievskaya would have been occupied somewhere else and Lambiel wanted to have his choreographer Salomé Brunner with him as a supporter at the competition, along with Petrenko. But the powerful (?) Russian woman said no. What was a 23-year-old supposed to do then? Continue being sensible?
"Perhaps Wayne was a letdown and he didn't want to admit it to himself" pondered Peter Grütter, his (Lambiel's) long time figure skating coach from Geneva. Four weeks ago a sport medicine specialist from Munich diagnosed, according to Brunner who accompanied Lambiel, that the current pain will wear off, that it is just a remainder of the adductor injury. Perhaps wrong decisions can also cause phantom pains.
[...]
The article continues to talk about Plushenko's surprise when he heard about Stéphane's retirement and about the fact that Stéphane doesn't seem to have a real plan for the future.
-------------------------------------
Now my opinion to this

. First of all, if this was a text to analyse, I would say that there are lots of "perhaps" and use of the subjunctive. But I guess the author interviewed Grütter and Brunner (have in mind that Switzerland is really small, which means that the journalists probably know lots of athletes and their teams in person). Now to the content.
They wanted him to learn Weir's spins? Nothing against Weir's spins, they are very good and solid - but not outstanding. The only rational explanation that comes to my mind is that they perhaps wanted to reduce the risk of injury (Stéphane talked in Japan, I think, about the pain he feels during the spins, how hard they are on his body etc.).
The thing with Zmievskaya being his actual coach and not Petrenko - well, I kind of expected that. After all Petrenko doesn't really have any experience. And that Zmievskaya is strict can't be too unexpected either. The thing with TEB seems to be rather minor though.
Perhaps we'll never know the real reasons. Because if he had been just uncomfortable in the US, he could have just returned to Europe. After he switched coaches Lambiel said that he thought about retirement right after Worlds - perhaps he just thought that going to the US is his last try to get back on track - and when that didn't work out so well he decided to retire for good.
After reading this article and others that elaborated a bit more, I wouldn't be too surprised if he reemerges in a few months or a year with new fantastic programs and reunited with his old team. Whatever he does, I just hope he will be sincerely happy with his decisions.