i didn't post about this the other day...
the ruling was a judicial review, which means they had to determine if the initial judge was "reasonable" or not. those arguments are always tough to win. the judge would have to fuck up in misapplying the law somehow. the review doesn't negate the judge's discretion.
now, it's sort of hard to compare environmental and financial costs. really, you'd have to quantify the environmental costs. that's hard for two reasons. first, it's predictive - whereas the financial loss for transcanada is costed. second, any quantitative approach is going to be insufficient to win the case. the real cost in terms of things like people dying can't be worked into the equation.
so, the sierra club made that argument - that they're incomparable, and that's how the judge fucked up, by making the comparison in the first place. yet, that was the nature of the suit! also, consider the precedent that would set. it's unworkable. of course the judge wasn't going to stand up and say "environmental costs always overrule financial costs because they can't be quantified". that makes no sense in any kind of existing context.
i've seen this sort of thing before, and it makes me wonder. i'll admit i'm having trouble coming up with a better argument. but it's obvious that one wasn't going to fly. did they really think it was going to fly, or did somebody get bought off? and did they assume nobody was going to follow the argument?
http://truth-out.org/news/item/19453-us-court-transcanadas-keystone-xl-profits-more-important-than-environment