Lightning cracks down

This was taken from the shelter of my balcony last week during a fantastic storm.

It was the only really solid shot I got, a couple of others had faint cracks, and I got one good one at the very corner of a shot. Satisfying to get any at all though. Patience pays off!

I can see a bit of a halo around the trees, I’m not sure whether this is an actually photographic artefact from the lightning or just some dodgy processing. Do you know? Do you know how to fix it?