Upon inspection after the break (of the crank), it was apparent that there was a micro crack that probably could have been spotted if one checked it over every day with a magnifying glass. Seriously, who is going to do that, especially for a part like bars that are under tape. It's not common, sure, but my point is that there were no obvious warning signs and it was a catastrophic failure. Carbon may be more prone to it, and the warning signs more hidden, but aluminum is not immune.
I agree that aluminum, actually nothing is immune given the right set of variables. but without the inspection one never knows for certain. That is the point I was making, most times we only learn of a problem after its to late with aluminum. with carbon its even harder to spot the problems because so much less is necessary to cause a failure. I am not saying to inspect your bike with a jewlwers loop, I say learn from these things, know that the curl of aluminum coming off the crank arm as you tighten the pedal on is a warning sign. ( I exagerate for illustation purposes) The micro crack tells the story, It presented as a catastrophic failure, but upon further inspection its not really. Could you have found it if you did inspect it before failure? who knows, but there was a chance. carbon would have let go when the micro fracture occured.
I am not saying that there is anything wrong with any of these materials except the reputation that they get when the facts arent looked at completely.
Justs for fun, there used to be a web site for failures like this one many good examples on there.