I would like to know more about those "special tests" in their "labs".
CR has a radio-frequency isolation chamber with a base station emulator in their Yonkers labs.
So, unlike all the so-called tech websites with their "let's try it in my basement" tests dependent on their local cell site congestion and arrangement, CR does repeatable scientific tests using equipment similar to what Apple showed off in their Antennagate press conference.
Personally, I'm a fan of using both lab and field tests
(The original iPhone had an audio volume problem that also should've come up in the lab, but didn't get attention until hundreds of field testers wrote reports.)
As for the iP4, Apple's problems were that 1) in their lab the phone was in a test rig, untouched by human hands, 2) test units in the field were covered by camouflage cases, and 3) Apple's penchant for secrecy meant that testers were unlikely to share coffee conversations where a common feeling that something wasn't right might've come up.