I'm not really amazed at the lying part, I'm more amazed at the practical aspects of all this.
- He has a video contradicting what he is saying and he continues to lie in court even after watching it?
- How did the prosecutor not catch this before trial?
- Why didn't the defense lawyer raise the issue in a pre-trial motion? The case would have gone away.
- Heck, why didn't the defense lawyer just go visit the prosecutor and tell him he had a problem with his case? Any prosecutor would dismiss it unless he was crazy or incompetent.
But using that lie against the cop in other cases is a heck of a lot more trickier than you think. It wouldn't surprise me at all if most judges wouldn't allow evidence of it based upon the Texas Rules of Evidence regarding impeachment. And they would probably be right.
Finally, I wonder how long it will take for a comment to say, "So what if he lied about the reason for stopping the guy? He took a drunk driver off the road! That shouldn't get the case thrown out!" (It's called the Exclusionary Rule for those interested.)