Give the license and registration FIRST. Your brother is a dumbass for not handing over the license and registration. If you refuse to provide license and registration, it's a huge red flag for the officer. 9 times out of 10, someone refusing to show license and registration is either in a stolen car or has a warrant out for his arrest.
By refusing to hand over the license and registration, your brother made the officer extremely uneasy. The officer doesn't know then if your brother is a fugitive or thief or whatnot and the officer has probably heard plenty of stories of traffic stops that end with the officer being shot by a felon who was pulled over in what appeared to be a routine traffic stop.
When stopped, you should turn the car off, put the keys on top of the dashboard, and keep your hands on the steering wheel and in sight of the officer. When the officer asks for your license and registration, you hand it over immediately, and only discuss the incident after that, if at all.
In my experience, the most effective conversations go something like this (after all of the above was completed):
Officer: "You were going a little fast back there."
Me: "Was I? I wasn't really paying attention to my exact speed, just trying to keep up with the flow of traffic."
Officer: "I had you clocked at 73." (speed limit was 60)
Me: "I really don't know how fast I was going, I was just keeping up with traffic flow."
Officer: "You backed off after I clocked you."
Me: "Traffic slowed a little so I backed off to keep in the flow. I didn't see you until you turned your lights on."
Officer: "I have to go back and run this through the system."
Me: "OK."
*Officer runs my license and my plates*
Officer: "I'm not going to write you up for anything, but try to pay more attention from here on out, OK?"
Me: "Yes sir, I'll definitely keep an eye on my speedometer instead of just keeping up with traffic."
Officer: "Just be safe out there, OK?"
Me: "Will do. Thanks!"
ZV