TexasCHLforum.com

The difference is between State Criminal penalties & Federal Civil penalties.

Under the Texas Penal Code, LTC holders must be afforded the opportunity to immediately leave the secure area of the airport to avoid being charged of a State offense. If a person doesn’t have an LTC (or a person with an LTC for some dumb reason refuses to immediately depart...), they get arrested & charged with unlawfully possessing a weapon in a prohibited location underthe Texas Penal Code..

But, this is totally separate from the Civil fine that is levied at the Federal level for possession of a weapon in the secure area (including the screening area). Without an LTC, your friend would have had both State & Federal repercussions.