Remember all the field test units were inside fake iPhone 3GS cases to disguise them. That said, I still dont think Apple would have let that sneak out with a massive HW fault like this.

That was a theory, yeah. But that has been discounted by a number of manufactures and prototypers etc. It was only the field tests. There will have been plenty on campus testing without the cases. One of apples fundamentals (It is like their 10 commandments) is about how the product feels so it is unlikely they did not come across the issue.

I hope as BIG questions need to be asked if otherwise though as knowing the above if it is hardware Apple launched a product with a fundamental flaw to get money and the US Guv and FCC and others who are already looking at a number of software practises at Apple would be on them like a shot and Apple would quickly be in the crap.
If found guilty and their software practises also Apples reputation would very quickly be ripped to shreds and they would be back at square one. This is not fantasy, they could really fall on their own sword.
They would know this know, it would be just mind numbingly stupid to think they could get away with that. It is just very hard to figure this would be the case, not impossible, but man this would be one of the biggest balls ups of a company. The arrogance, the stupidity and guts to think they would get away with it, just can not see it as likely.

It is more likely that because Apple are supposed to make perfect products all the time, I like their products but they are far from perfect, I have yet to by something that has been close to perfect though. BUT apple tout themselves in that way and so when a product has issue a big fuss is kicked up about it. This could all be just blown out of proportion and the software update fixes it and could have been something that appeared as a result of a change or tweak in the latter builds of the OS.