What are these bubbles during a lightning strike?

[Another Kent clipper]

Hey there.  I grabbed a still from a YouTube video of a storm in Bournemouth and noticed some odd artifacts from the moment a close strike hits:

Any ideas what these are?  The original video is below and the screenshots were taken from 8:52. I'm sure the author won't mind me mentioning this here

 

Edited July 13, 2017 by Another Kent clipper
I realised it is almost certainly rain. But what a strike!

[Another Kent clipper]

The url is wrong btw. It should be https://youtu.be/EWTFIcpPOCM

 

[4wd]

It looks like the camera reacted to the lightning flash quickly enough that shutter speed was fast enough to freeze large round raindrops.