Originally Posted by
swag
If this was the gate agent as you were boarding, then this was not a TSA encounter and has nothing to do with security. It's the airline agent being over-zealous when enforcing the rules.
In my experience, strictness about number and size of carry-ons varies mostly with the individual agents. Trying to associate it by airport or by airline usually is inaccurate when you have a larger sample size of more trips.
DFW is my home airport, and I haven't noticed them being unusually zealous, for me or for other passengers.
There also appears to be a functional relationship between FAA oversight at that moment, and fines given/threatened by the FAA to the carrier.
Didn't DL recently go medieval on carry-on dimensions, after some FAA actions?
Remember, the airline submits their processes, the FAA insures the carrier is following them. These are rules that have always existed, and differ from airline to airline, yet yes... a neck pouch seems sorta odd.