Originally Posted by 42psi
However the US always did at that time .. and apparently still seems to .. let baggage travel without the pax .. from my previous dealings with US carriers I actually believe they don't in fact know what baggage is on an aircraft

Which is hardly a robust state of affairs for anyone planning a terrorist attack! Hey, maybe that's the plan - make baggage carriage a hit and miss process, thus making any terrorist attack more of a lottery - brilliant!
Reading the OP's comments, Delta must be somehow liable for initially emplaning his bags without him onboard, but also perhaps for the resultant rough treatment by the TSA. But I'm sure both will find a dodge, somewhere behind 9/11 hysterics. I was always surprised by the policy of leaving luggage unlocked at check-in. Unless baggage is handled like cash - which it clearly isn't - doesn't unlocking it simply provide more opportunities for a rogue baggage handler to slip a device inside?