Why Apple did not know about the iPhone4 antenna problem

(IMO) That is easy to answer, because of Apple super secrecy they were testing the new design inside a case to make it look like the old iPhone. So the antenna was isolated from the user hand with enough distance to minimize the effect, and I am certain that it was also the case inside the company since they don’t want the other employee to know about it, but thanks to Gizmodo this thing was unveiled. In addition to that, they most probably have a big AT&T cell tower inside the company to make Steve happy.

Image from Gizmodo of the iPhone4 with the special case.
The camouflage case
The case it came inside was a fully developed plastic case to house this phone to disguise it like a 3GS. This wasn’t just a normal case; it had all the proper new holes cut out for the new switches and ports and camera holes and camera flash. But it looks like something from Belkin or Case-Mate. It’s a perfect disguise.

Source: Gizmodo