I don't want to sound conspiracy minded here, but some of you may have seen that this exact scenario played out with the Shimano ICE tech rotors on the XTR test in one of the German MTB magazines (from the same publisher as Tour) a few years ago.
It caused a similar hubbub, as generally the German magazines seem to bring a nice degree of objectivity to testing of parts, actually measuring stiffness of frames and wheels, stripping frames to confirm weights, measuring crr of tires, etc...
If memory serves, they got the XTR rotor to fail in both lab and outdoor riding settings, which provides more exacting data on what the conditions were. Here is actually a little translated summary of those findings I found: "The "XTR Melt-down" happened firstly at Fade-Test when constant hand force of 115N was applied on brake lever as many times as needed either to reach maximum of 40 cycles or critical temperature of 400*C was gained and test must have been cancelled. Both XTR XC with organic pads and XTR Trail with metalic pads melted the aluminium "core" of their Ice-Tec-Rotors (alu-core seems to be the alu part of rotor?) and disc rotors deformed!
Practical-test only confirmed the result of Fade-test from lab. During the test ride, all Ice-Tec-Rotors melted. The alu-core of rotor got very soft and "was stuck in combination of greater heat and force required" (my interpretation). Test rider weight was only 75kg / 165lbs.
After they used and destroyed all Ice-tec-Rotors they replaced them with some standard/classic rotors that behaved much better. But even with these brake the mineral oil "rised up all over the set up" (I can't translate this). "
Either way, that was 3 years ago, and so far I have seen no real world reports of this occurring in the field, even when used on a Tandem. In addition, Shimano claims they were unable to replicate this type of failure in the lab.
So in short, I have to wonder about the following:
A. If this was a real issue why wouldn't it have surfaced from more sources in the past 3 years.
B. If there was a real risk, why wouldn't Shimano have discontinued manufacture of the rotors. With all of the lawsuits and recalls in the bike biz, how could they stand the risk exposure of a fundamentally flawed brake?
C: Ergott mentioned above that Alu melts at 660C whereas the MTB test protocol seems to stipulate that they cut the test off at 400C. If those figures are correct, the discrepancy should be obvious.
If their lab testing exceeded any conditions reached in the real world, I could understand the possibility of a failure in the lab, but none in the real world. But in both the MTB and Road cases here, they seem to have achieved failure in the real world too.