No, I didn't think that the Brits were violating any GC's here, it's not really their hand in that to play at the moment & I would hope that the same goes for the Iranians too. But that question should be asked all around, we sure weren't abiding by it. Though I did see a video of them on the news eating & looking in good condition, I'd say it was more to show decent treatment (or at least portray that) of them rather than the photos being used as a threat, hopefully.
The picture of the airman holding a hand held GPS is likely to be showing his own vessel's (Cornwall?) position & not the dhow, that is not a dhow he's hovering above, so where they boarded & where the dhow was is still very much in question & we do know the Cornwall was out of site of the boarding vessels (at least I think we do). The distance of site of horizon at a height of 6' is 7 miles at sea in calm waters, though beyond a mile or so it's difficult to spot a small vessel anyway, the higher vantage point the better. So if the sailors in the boadring vessel couldn't see the Cornwall they could've been a min of only a few miles away or they could've been at the least 7 miles away or better, I'm sure the the Cornwall sit high enough to get a good long distance view if they were watching (God help the sailor who wasn't & was suspossed be). At this distance did they know where they were when they boarded & after they finished?
On the news this evening I did hear an apology but it wasn't from the female sailor it was just an apology from no one in perticular. But at this point in time an apology means nothing & may never come to mean anything. We can only guess. She'll say whatever her government tells her to say after it's all said & done with.

Barry