I love cops. But as Stephen King notes of police hiring practices in his latest novel, Under the Dome, "You buy cheap, you get cheap." It follows that some are not so deserving of the faith we tend to put in them.
Professional courtesy is a phrase that gets tossed around and debated on the listserve Police_L. It is something that I suspect most practitioners of similar ilk extend one another. However, it is not something that should be extended lightly, and there are those who have extended a "professional courtesy" to a fellow officer and regretted it, either because the guy went out and did another DUI, or because he spouted his mouth off about the amnesty and the wrong person (or the right person) got wind of it.
Regardless of which side of the equation you may one day find yourself on, it will help to have a game plan in place ahead of time.
I don't imagine most cops lie awake at night wondering how they can hook up another officer. If anything, they wonder how they can avoid it.
One thing you can do to prevent negative situations is to model good off-duty behavior yourself, and reward it when you come across it. Another is to not reward bad behavior.