Legal Question in Family Law in Texas

Well, probably not. You're right, that's only 30 days and you're not supposed to remarry until the 31st day. There is a provision in there that allows a judge to waive the 30 days, though, so you never know--anything's possible. Given that particular timing, though, my guess would be that they counted wrong (non-lawyers tend to sometimes count the day of the precipitating event as "Day 1", instead of starting with the next day).

However, the odds are good it doesn't much matter--it's not going to be considered bigamy, and won't affect the validity of the new marriage at all unless the new spouse honestly didn't know about the divorce prior to the marriage, had no reason to know about it, and when he/she found out, was upset enough to respond by both immediately leaving their new spouse AND petitioning for an annulment within a year. Which I think is probably unlikely to be the case, given the timing on this. Being aware of the divorce itself, but getting confused and thinking the 30 days had passed, but finding out later that it hadn't won't justify an annulment.