No -- TSA policy requires them to investigate all "anomalies" with a pat-down. If they saw & ignored it, they completely broke policy, which is another problem with the nude body scanners: a metal detector has a loud alarm and can't be ignored, whereas an x-ray screen can.
This has been what I've been wondering. While going through HNL a few weeks ago my girlfriend forgot to take her cellphone out of her bra before going through the backscatter. Nobody said a peep.
What are the chances the TSA wouldn't select you for additional screening upon detecting any metal on your person going through a body scanner? Serious question, no snark intended.
I doubt that - they'd be taking a huge chance. Even if it wasn't explosives, the person could've been keeping drugs inside that metallic object and thus would warrant attention.