TSORon, are you saying that that passenger has to provide the TSA with an ID, or that the TSA requires it's agents to identify the passenger? The difference is substantial and important.
As to
49 CFR 1540.105(a)(2), it does not say that providing an ID is a system, method, or procedure for entering the sterile area. It doesn't even mention ID.
Moreover, not even Blogger Bob claims that showing an ID is required. Instead, he says that the "identification requirement" is one method the TSA uses.
The blog you reference says:
Bottom line is identity matters. We need to verify who is getting on the plane.
The best and quickest way for us to assure identity is with a photo ID issued by a federal or state government. We work with passengers who have something less than that, including no ID.
(emphasis added)
Bottom line, although a passenger showing an ID has the advantage of speed, even Blogger Bob says no ID is required.
If you have evidence that the "identification requirement" is that the passenger show an ID, please provide it.
Finally, I thought the Phil Mocek trial put this issue to rest.