Not necessarily, but the the chance of any crazy coincidence happening and reaching HN homepage is quite big. Next time it might be two people with same name writing the exact same tweet independently. Or perhaps one guy winning the World Series of Poker two times in a row with the same winning hand.
When there's a million "kinds" of crazy coincidences, the chance of any one of them happening is much higher than chance of a specific one happening. This is kind of a selection bias, we only hear about the coincidences that happened.
The odds of the same person winning the WSOP now at all are significantly smaller as the fields have grown so much, never mind the compounding of winning it with the same hand twice :)
(To clarify, it was not the exact same hand - different suits in each case. But still pretty remarkable!)
And storms do not happen that often, even in places that have them "frequently", and they delimit the time, and even further by e.g. limitations such as whether the wind is too strong or the rain too heavy.
The number of locations they're likely to consider good spots to take the photo from for a given landmark may not be that great either. Both in terms of where you can actually see the landmark from, and in terms of other factors (e.g. in this case the article writer points out that both photographers had found places where they could protect themselves against some of the effects of the weather)
So that narrows locations and timeframe significantly.
Professional photographers are likely to take their time - the article writer mentions 40+ minutes of shots, and using bursts, further increasing the chance for an overlap within already relatively narrow time frames.
Additionally, external events that are the same for both (the waves) will give impulses to both with respect to when to shoot (though of course they might value different things, I'd argue people are more likely to shoot when something dramatic happens - e.g. if you have a dull day and suddenly something happens, you don't expect the pictures of that day to be evenly spaced afterwards).
I'm not saying we should expect it to happen all the time, but I also think it's easy to overestimate the number of possibilities because we've not tried to enumerate which ranges of values are actually likely.
Anyway, that low probability applies to every other photo. So, the first photo is compared to every other photo and by the end your talking ~50,000,000,000,000,000,000 comparisons. The odds would have to be mind boggling tiny for this not to happen all the time.
Another way of thinking about it, what are the odds that out of the ~1,000 photos taken of the same moment they are of the same subject? Now repeat that question 10 million times and the odds don't seem as low.
That they're professional photographers might reduce the odds by virtue of there being fewer of them, but might increase the odds by virtue of them being more likely to be the kind of people to know of specific spots to go out of their way to take pictures from during a storm, and more likely to value the same qualities i their shots, as well as more likely to publicize their photos enough for one of them to find the other persons photo.
While technically the world is discrete in space and time (planck length), for all intents and purposes it is infinite in practice.
[1] yes, there is countably infinite, but that doesn't work with the pigeon hole problem.
In other words, two photographs off by a planck length will generate the same set of pixels.
How does that not apply to this situation? The number of comparisons between photos is much much larger than the number of photos.
It might not apply in a way that is interesting mathematically, but I don't think that is what the other poster was getting at.
Re-reading the article, I think saying the pics were shot at the "same millisecond" was just a colloquial expression to mean the look of the waves makes it look as if they were shot at the exact same time. They shared metadata but that seems to have been to share the other shooting parameters. I believe (and this would seem to confirm [1]) that EXIF timestamp data is only precise down to 1 second. added: and only as accurate as the photographer who set the date and time.
[1] https://www.media.mit.edu/pia/Research/deepview/exif.html
Working with images from multiple photographers cameras who haven't gone out of their way to sync the time beforehand, I've usually had to assume about a 10s time skew. They do not have precise clocks and are not sybchronized often.