http://www.dailymail.co.uk/news/article-2540092/not-good-day-to-be-at-the-beach.html

Wonder what the odds on that were

About the same as Big Sam managing Real Madrid.

If that car hadn't got in the way and the photo was taken a few milliseconds earlier, it woud have been a true memorable money shot.

But as it is, I should imagine it must have been frightening and upsetting for those around the poor lass. A good example of being careful what to wish for in terms of wanting proper stormy weather. 

4 people killed on a beach in Argentina last week too.

A beach must be similarly risky to any open area, although I don't recall reported incidents previously.
Sports fields and golf courses are most often in the news as people there are distracted and have an incentive to stay out till the last minute.
You don't usually stay on a beach until a storm is very close.
You can get bolts well ahead of an obvious line of activity of course.

I think it's likely to be a still grabbed from footage from a video camera - very likely gopro or similar.

Yes, that makes more sense. I thought the timing looked suspiciously good. Still intrigued by those little "fireballs" though.

I remember being on a beach in Cambodia when a sudden downpour approached, with lightning coming down pretty close (although not THAT close, fortunately!) All the same it was pretty terrifying and I sprinted back to the guesthouse I was staying at in record time. (And had the bonus of seeing a funnel cloud from my balcony when I got back!)

I've been scared by sudden thunder twice - once we were up on high moorland and it was thick fog as thunder rolled around.
I had a dog that did not like loud booms!
It seemed best to crouch by a large rock until it passed.
It felt like we were literally inside the cloud as it dragged over the high ground.

The other time was at school.
It was lunch break and a lot of us were hanging about on and around the football pitch.
This was the 70s and a lot of the lads had long hair.
Suddenly laughing broke out and they were pointing at each other because several of them the fine hairs were starting to float up and literally stand on end from static build up.
It wasn't obviously about to be a strike, as we had heard no thunder - but seconds later a bolt hit the adjacent farm field.
We were lucky that day but did not realise until later.