TexasCHLforum.com

The attempt to get the blood draw thrown out under section 724 has already been tried and failed at the Texas Criminal Court of Appeals. So that is settled law. There is a fairly in depth discussion of it here:
http://www.russellfrostlaw.com/no-refusal-weekends/" onclick="window.open(this.href);return false;

Apparently the courts have decided that the power to use a search warrant overrides section 724.