Commentary on new Texas law

The former Texas law outlawed carrying by non-CCW permitees unless a person was "travelling" (a proviso that dates to the last century). There was no definition of travelling ... was it across town, on a walk, only to another city, or what? The new statute says a person is presumed to be travelling if they have a concealed firearm in a vehicle and are essentially not a bad guy (felon, gang member, etc).

Problem is that law enforcement in some areas is ignoring it, on the principle that it's a presumption, and you can rebut presumptions with evidence. So one has told his people to arrest unless the person is going on an overnight trip. If a person wants to argue the presumption protects them, they can tell it to the judge.

A thought: if TX follows the usual standard, an affirmative defense (which this is) has to be established by the Defendant with a preponderence of the evidence (more likely than not to be true), and then the prosecution must try to refute it beyond a reasonable doubt. In this case, tho, the presumption would mean the Defendant *always* has established it at the outset. In that case, might the arresting officer be open to a false arrest suit? At the time of the arrest, he knows the person has an affirmative defense. If he does not CYA by questioning, to get some evidence to argue that the person wasn't travelling, or if the info he gets does not show that the defense is inapplicable (gun wasn't concealed, person was a bad guy, etc.) isn't he making an arrest without probable cause (variously defined, but at least strong suspicion this guy is breaking the law)?