I never knew it was defined as a switchblade there...
But Texas is also a big place, adn LEOs do things differently in different places. I've known people who got in trouble for normal folding knives, because of intent, but I've also seen people carry other stuff, and be let off with a warning once the LEO judges him to not be threatening. Especially with all the gun shows etc in the area. I've seen people go relatively unmolested that were carrying regular switchblades. I was in Houston, which can go either way. Usually if you're compliant and polite and PATIENT the LEOs will return the favor after the initial getting to know you part of the interview.
Personally, I find the laws to be a little strange. I just moved to MA (yeah, damn yankee now, I know) and you can have balis shipped to TX but not carry, whereas here you can't have em shipped, but you can belt-carry.