The problem was that the car in front of us panicked and slammed on its brakes. My FJR strained under the antilocks to stop in time, but my friends bike got a bit sideways placing him in the next traffic lane, which was fortunately un occupied at the moment. This has been the first of two close calls for me because of these flashes.
You mentioned that your speed at the time was reasonable. Perhaps your following distance wasn't quite enough? We're all aware that drivers do some obscenely stupid things and that the onus is on the rider to anticipate and avoid.
I do agree that the driver should NOT have slammed all on, just for a flash. In a perfect world, he would have been driving at or below the limit and not had the need to make a panic manoever. The world is not perfect, so we're all reminded to stay back. They're out to get you!!
(Glad you and your buddy made it through OK)