The launch happened right after sunset, but the rocket has to go up many kilometers. So when we were seeing this, the rocket was in sunlight but the ground was in the dark. This meant that the sun was illuminating the giant gas cloud of exhaust coming out of the back of the rocket.
It was incredible seeing it. I had forgot about this launch and was driving west from east San Diego. Turned a corner and saw this incredibly strange glowing line in the sky. It took me a bit to realize what it was, then I got to watch the landing!