Originally Posted by Deep 3.2TL
There's something more that's happened here - to get these beams of light so perfectly, just leaving the shutter open wouldn't work. You'd end up with a ring of light, not straight beams.
my only other guess would be sport mode multi shot.
but if you look at the gate .. he used a flash as well.
now if the flash is used it would take some of the beam light away .. if the flash flickered a couple of times while the shutter was open it would have that effect.