http://www.bladeforums.com/forums/showthread.php?t=337021&highlight=texas
i don't live in texas, but from what i've read i think the answer is similar to that in some other states. assisted openers may technically operate in a way they they are not semantically (in the words of the law) a switchblade, but their function is very similar to one. if you carry one you risk being harrassed and possibly cited/arrested, even if a lawyer may be able to vindicate you later. the power is not in your hands, but in the interpretation of the law from the cop you're dealing with. that's not a comfortable place for me. personally i'd leave the assisted opener at home most/all of the time, and EDC something else. there are some many other great knives out there that are clearly legal. but that's a personal choice.
there's a good chance (well, depending on what you look like, what you're doing, and who the cop is) that you'll never have an issue. But the leek is a slightly aggressive looking knife (the fact it scared that woman at your work is evidence of this), and someone could easily make your life miserable if they wanted to.
so really, i think whether it's actually legal in the end or not is not what's important. the real issue is whether or not carrying around a knife that opens neat is worth making yourself vulnerable to someone elses legal whim. is it worth it?
that being said i have a kershaw scallion. cool knives, good bang for the buck. although i usually EDC something else. but i understand your interest in blades for utility, and desire to carry something convenient, functional, unique, and cool. i feel the same way. the laws don't always seem fair to legitimate knife enthusiasts who carry for utility like you and I, but i understand why they are what they are.