Meadmaker: Yes, David most definetly would
The flash discharges much faster than the shutter speed of the camera, but since this scene was already well lit before adding the flashes, lowering the shutter speed would mess up the "freezing" as you point out yourself with the nice 3 image shutter speed tutorial. Shooting the same scene in a completely dark room, you should be able to freeze the water with the flashes alone, even if you had shutter speeds of 1 second or more
With regards to the flower, it was lit by the flashes as well, since both flashes were pointed at the water in a 45 degree angle from each side of the camera. There were no gobo's to restrict the light.
Sander: Like your kitchen sink photo. Great color!