Ok I'm going to attempt to explain what the officers did and why from my 15 years as a police officer. You can feel free to disagree, and I'm not going to say the officers handled it in the best possible way, but hear me out. I don't normally post in these threads anymore because of the overwhelming anti-cop sentiment (often justifiable, often not) on this board.
A furtive movement is something that appears to a trained officer to be movements that are suspicious and can possibly believed to be trying to conceal something which may be dangerous. You admit that it took you longer to pull over than it should have because you didn't see or hear the officer behind you. Look at this through the eyes of the officer. Most good drivers check their rearview and side mirrors every 5-10 seconds. Couple that with moving to take a drink (which the officer obviously can't see) and you shifting your transmission (again can't see from behind), give the impression that you may be intentionally hiding something before you pull over. That's furtive movement.
Now he asked you to step out of the car because a) the movement could indicate that you were hiding a weapon under your seat (a reasonable assumption based on you not pulling over and your body movement) and b) the officer doesn't need a reason to ask you to step out of the vehicle. We can have ever person get out of the vehicle on every traffic stop if we so choose.
After stepping out of the car, when the officer looked in your window, he was looking at the seat and center console area for anything dangerous or in plain view. He does not need your permission to look in your window. If you were still sitting in your car, would he not be looking in the window to talk to you? Dropping your "I don't consent to any searches" that you learned on YouTube doesn't earn you any points with police.
Now add the fact that you put your hands in your pockets. Officers are trained to watch people's hands very closely. He already believed you might have a weapon in the vehicle, it wouldn't be unreasonable to make the connection that instead of putting a weapon under your seat, you could have also put it in your pants, which is why he yelled at you to not do that. The smartass comment about not wanting to be shot didn't help your case.
There is supreme Court case law on exactly what the officer told you. Just like Terry v Ohio allows pat downs for weapons without probable cause, there is another case that does the same for vehicles. I've never heard of the term "lunge area" but it's more commonly referred to as areas of immediate control. Which from the seat where the person in question was sitting, is anything that is within reach. Typically under the driver's seat, front floor, glove box, center console, and under passenger seat. No warrant or probable cause is needed for these searches for weapons.
The second officer was there because that often happens if another officer happens by during a traffic stop of another officer. Or he could have called for backup since he thought you might have a gun.
So the not pulling over and your body movement from the officers perspective from behind you made him believe you were hiding a weapon. This is called reasonable articulable suspicion and can be used to pat you down or do a protective sweep of your vehicle without your consent.
The key is that the officer has to be able to articulate it. And in this case based on what you admitted to, the officers did meet that threshold of reasonableness.
Now you can argue that they were rude or whatever, but that's secondary to everything else.
Hope that helps
