Given the nature of the first post, I've stayed out of this so far.
I'm going to try to avoid rants, on either side.
What I suspect we have in this story is a smartass who decided he had a chance to get over on a cop. I'll go out on a short limb, and predict that many of the charges he made get dismissed, in part because there is a good deal of overlap. The charges were, according to the article, illegal stopping, illegal parking, "obeying parking regulations on a highway" - I suspect an error there! -, and illegal operation of an emergency vehicle. I've not reviewed the Oregon laws, but it seems that there was quite of bit of overlap between some of those charges, and I question whether the last was at all valid. (I see nothing supporting the validity of enforcing the sign at all; not all signs are legally enforceable.) But those are matters of fact or law for the judge to decide.
Let's look at what happened. A police officer, going about the course of his day, pulled into a restaurant, and picked up a meal, apparently to go. While waiting for the order to be delivered, he watched a few minutes of a ball game. There's no indication of the actual duration of the alleged parking infraction, but it seems to have only been a few minutes. When a fellow patron of the restaurant questioned him, the officer gave what I suspect was a rather sarcastic response about needing to be able to leave quickly. The patron took advantage of his knowledge of the law to get the last word by obtaining charges.
So... let's look at police officer parking. When I was in patrol, I generally tried to park reasonably in light of my duties and activities. If I was simply stopping in a business or checking the area, I used legal parking spaces as much as practical. But I had to keep in my the simple fact that I was still subject to calls; it wouldn't help the public if I had to respond to an emergency with a ten minute trip back to my car. At the same time, a cop car parked illegally with no apparent justification is just one of those things that (justifiably) irks the public... I'll admit to having done some creative parking on occasions, or taken advantage of being able to park in loading areas or other places that aren't generally available to the public. After all, nobody's gonna tow a cruiser, right? But the simple truth is that cops on patrol do have to be able to get back to their car quickly, and get out quickly. Sometimes, the normal parking isn't amenable to that.
I do think the officer could have handled the situation better; a sarcastic remark almost never improves a situation. Had he taken a moment to explain things without sarcasm, perhaps it would have gone no further.
Regarding police driving in general... There are a number of things cops do on duty that they discourage others from doing, sometimes even by citations. Let's begin with the most obvious... Multi-task while driving. A typical cop on patrol is: driving a car (which is already multi-tasking!), listening or talking on a police radio (sometimes covering several frequencies), listening to the "fun radio", looking at messages on an MDT/car computer (if he has one), looking for traffic violations, looking for other violations, looking for suspicious behavior, and doing all the usual mental gymnastics of life. Some do something I personally think is unprofessional, and chatter on the cell phone. (Note that work-related calls are a different question; some things cannot be sent over the radio.) Cops also routinely do things that are outright violations of the traffic code, like turn without signals, or drive faster, use cut-throughs and cut around parking lots, and more. I hope few cops routinely run red lights without justification -- but I'm sure some do. Similarly, some cops will flip the blue lights on to get through an intersection, then turn them off again. There are reasons why they may do this with justification (some calls should not be responded to hot, but are still urgent, or get cancelled as soon as you get started for lots of reasons, for example), and some are just lazy. Many cops don't always wear their seatbelt, because we may have to jump out of our car suddenly and unexpectedly. They are often exempt from wearing a seatbelt, as are (in Virginia) taxi drivers, and postal and other delivery drivers.
The operation of a police car is one of the things that most often causes dissent for all these reasons. It's also something that causes huge liability for departments. Each agency and each officer has to balance the operation of a police vehicle with the demands of public safety as well as public relations. Officers are subject to discipline for actions that an ordinary driver is, at most, required to fix the damage. (I know someone who got disciplined for simply making contact with a post -- no damage to either cruiser or post!) And officers get complained on for things that are sometimes mind-boggling when driving; I once had someone complain that I was driving too fast while running lights and sirens to a call!
Now, let me return to the original situation. It's something I've seen happen a lot. Usually, unless someone was parked in a way that was causing a major safety problem, I would wait a few minutes before writing a parking ticket. Sometimes, I'd go inside the business, and suggest that the driver needs to move the car -- or else. Because I sometimes had to do the same thing, for reasons I've already discussed.
OK... one short soapbox moment. If you're concerned about the behavior of cops, there's a simple approach. CONTACT THE AGENCY. If it's about driving or parking, note the time and vehicle number, and the location. Complain. In many agencies, even an anonymous complaint gets investigated, no matter how small the matter. That cop has a supervisor, even if he's the chief of police, who answers to the mayor or town manager or whoever. It might be there's a legitimate problem -- or it might be that the officer has justification for what he or she was doing. But the brass can't address the legitimate issues if they're never told of them. I have had weeks when I had very little contact with my supervisors (in my current assignment, I answer to two sets of supervisors -- and can still have days go by when neither set sees me because of my duties), and that's not uncommon for cops. Just like we rely on the public to be our eyes and ears for crimes when we're not there -- you're also the eyes and ears for the supervisors.