Looks pretty real to me. Pause it at 0:27 seconds (this takes skill because, as MSB says, it's going 3K MPS). The entire scene is lit up.
That's because they brightened the frame a lot, to the point of washing it out. Look at the shadows. They don't change one bit. Lightning is uber-bright. When the fake lightning "hits" the guy the first time, he's standing near the front of the first vehicle. Note that vehicle's shadow. It does not vanish or even dim. If you create a shadow with one light and then shine an even more powerful light on the shadow, it will be affected in some way. If that's not enough, look at the second vehicle. Absolutely no shadow is cast by it along the line from the fake bolt.
To wit:

Edit:
Even better, compare this screenshot from the video:

To what I just did in a few seconds (sans lightning bolt and grainy effect):
