Not being there I can't comment on this specific circumstance but there are some standard things about police stops that people need to remember.

First and foremost is that police can't actually control where an offender stops, all they can do is signal them to stop, but the police officer is not in physical control of the offender's vehicle, they stop where they stop. It's entirely possible that the officer signalled the person to stop a block or two prior to them actually stopping. Once stopped, an officer is not going to ask the driver to move his vehicle again unless absolutely necessary. Second, police almost always stop a foot or two to the left of the offender's vehicle to provide a walkway for themselves safe from traffic. They use their car as a shield to keep them from getting hit from behind.

As much as it may annoy people for them to be in the way for a little while, the fact is that traffic stops only take 5 or 10 minutes and have little impact on traffic flow as a whole. The car wasn't there very long, you just so happened to be unlucky enough to ride by while it was.

The PA thing was rude, but as much as we'd all like to believe otherwise, cops are people too. You make a sarcastic remark to a person, you're likely to get one back, regardless of who you're talking to. Yes cops are held to a higher standard, but most speak to you in the same manner you speak to them, whether that be good or bad.