Danno, I have a question. If you were stopped for an equipment violation, and I begin to develop probable cause of intoxication due to odor of intoxicants, bloodshot and watery eyes, slurred speech, but your driving was OK, I should ignore it? Let's say I disregard the odor and other stuff and since you were driving OK, I let you drive home and you get in a crash down the road, will you sue me for letting you drive? Maybe your level of intoxication is climbing. The sad thing is I have arrested many drunk drivers and most of them thought their driving was just fine. That's the thing about drinking, many times you think your are just fine.
Also, I don't think we enforce drunk driving laws harshly enough. There is nothing so frustrating and heartbreaking as investigating a fatal traffic crash where the drunk driver caused the crash and kills some innocent person.

jfmckenna,
The .04 the other poster was talking about was a DOT rule for those with CDL's. I don't have any problem with that. If they don't value their livlihood and better than that, they deserve to lose their license. I have arrested several with CDL's and one was even in a semi. They tried to make me feel bad because I would cause them to lose their license. No, they drank, I didn't pour the alcohol down their throat. Also, taking a breath test immediately after using mouthwash will give an unbelievably high BAC. Indiana law requires a 20 minute wait time from the time I stop them to the test. This allows residual mouth alcohol such as mouth wash to disipate and not be a problem. I am sorry your friend may have been falsely arrested. That is what the courts are for to determine guilt or not. If the officer arrested him maliciously, then he should not be an officer.
Sobriety check points are a recognized and approved tool for enforcement.