Folks, there is nothing written anywhere that says a police officer must have lights and sirens activated to legitimately "break" traffic laws. He/she could have easily been responding to a call, and speeding necessarily to get there quickly. Same goes for flipping on the red/blue lights to go through an intersection... it'* done all the time to speed up response time to calls, but there is no reason for the officer to leave the lights on when driving in a straight line with no traffic. I had this explained to me by an officer long ago, and frankly... it makes sense.
Current GMs: '95 Chevy Suburban C2500, '69 Pontiac Executive
Former GMs: '83 Buick Park Ave, '73 Buick Electra, '92 Chevy Caprice 9C1, '98 Pontiac Bonneville SLE, '99 Olds Aurora, '00 Buick LeSabre