The comments of the original article are very interesting, actually. For one thing, very few people support the author's version of what happened.
The fact of having been present somewhere is obviously a powerful device to employ to lend credibility to your account, and Lynas is playing that particular card to the full here. Yet various aspects of his account amount to little more than his own guesswork. He has no idea what China's overall "agenda" was, particularly as it conerned the PR battle with NGOs and Western leaders. He has no idea what Sudan's overall motivations were. He is offering his own speculative interpretation of events, and giving it rhetorical force with the vocal declaration that "I was there". But the mere fact of presence does not give you the ability to read minds. And that is what most of this account (read it carefully) consists of.
Other parts of this account give cause for serious skepticism. Mark suggests, extraordinarily, that the US's offer was "serious" - even though, as David Wearing has very rightly pointed out above, all they were offering was a 4% cut on the 1990 baseline, and in the context of all the issues of historical responsibility, equity and relative per capita emissions we should all be well aware of by now. It's not difficult to see how and why that might reasonably be construed as a pretty insulting offer.
Mark also suggests that the US "was obviously prepared to up its offer". So what's the evidence for this? It certainly seems to conflict with the details reported by this paper in the late stages of the summit, which point to the fact that the US was simply not budging on what it had already offered. If there's real, substantive evidence to the contrary I'd love to hear it, but all we seem to have at the moment is Mark's reading of what was "obvious". And given his highly flattering reading of what was "serious" in the US's proposal, I'm frankly inclined to take that with more than a pinch of salt.