What I have found is that TX ranked 41st in both 2006 and 2007 for number of doctors per 100,000 population, despite those 26000 new doctors in TX. The tort reform bill was enacted in 2003. What kind of improvement is that?
The 2011 Statistical Abstract: State Rankings
Exhibit 5.8: Non-Federal Physicians per 100,000 Civilian Population, by State, 2004 - Kaiser Family Foundation
The numbers of doctors are going up in all states, not just TX. The tort reform had little, if anything, to do with that increase in doctors to TX. In fact, it is quite possible that the tort reform could have led to less qualified doctors to move to TX, since they are the most likely to be worried about medical malpractice suits.