How Can Listening To A Legal Seminar Presentation While Jogging Make Me Stop Down?

(She's not related to this post. I've heard her seminar presentations. I'll never do it again.)

I was listening to a legal seminar the other day and heard a fascinating one given by a prosecutor from  Tarrant County. (Actually, he referenced "Ted Talks" which I mentioned earlier.) I've know the guy for years and he is smart, very good at what he does, and I've never heard anything other than positive comments about him. His presentation was about jury selection from the "State's Perspective" in DWI cases and it was fantastic. I know that because he was making me cringe as he reminded me how tough my job was.

But one thing got my attention. He spent some time on how defense lawyers, when there is not blood test or breath test in a case, will ask the jury not to convict based upon the opinion of an officer about whether someone is intoxicated. He pointed out how he will ask the jury panel if they have ever relied  upon a doctor's opinion or, when buying a new house, a real estate inspector's opinion.  If someone has expertise in area, he said, we rely upon those people all the time. He presented it very skillfully. But his point was that he tries to have the jury understand that a police officer is an expert on intoxication and the officer's opinion should be relied upon as well. (I rolled my eyes when I heard that but I digress.)

He was speaking primarily in front of criminal defense lawyers and I'm guessing he sensed their cynicism. But, and this is the point of this post, he actually said this: "So who am I talking about? I'm talking about your police officers. Um . . . hopefully. Now again, some of our police officers . . . got to keep your credibility[*], you know. And some, some of my officers -- I'm not going to buy that house. Even after they look at it, I'm not going to do it. And I'm just going to get them on and off the stand as quickly as possible and hope that the cross [examination] is going to be limited."

That really bothered me. Is he saying a prosecutor at trial should ask an officer an opinion on intoxication when the prosecutor wouldn't rely even personally rely upon it? And pray that the defense lawyer is so bad that he won't expose that the officer is no expert at all? Should a prosecutor later argue to that jury that the officer's opinion should be relied upon?

It's been about two weeks since I heard it and it still sticks with me.
*Incidental point: I'm not exactly sure what he meant by this phrase, and I've listened to the mp3 ten times. It may mean you have to keep your credibility "as a lawyer in front of a jury panel" but I'm not certain.