Too tired to do the actual math but considering the probability of someone getting a lightning (roughly seems to be 2 per race) and the time of an average race (about 2 and a half minutes on the generous side), the chances of you being hit in that window is incredibly small.
Then you take into account the probability that a track you hit doesn't have any mandatory glider sections or any sections it has is less than a second long.
Also take into account that since punishment for falling is less strict now, you can pretty much get back in anyway.