I did try to find a good report, the one on the BBC says it comes from the Sun so you can forget that one, and rest are not very good, so you have a number of things which could have happened.
What I am considering is if the extension lead fell into the bath then it's nothing to do with an Iphone, same goes if the charger was not a genuine Iphone charger, so there would be no point sending the report to Apple. So fact that Apple was to be alerted we are lead to believe it was some thing to do with the Apple product.
So I have considered what could have been wrong with the Apple product? I would have expected to see
this marking meaning it is "Safety isolating transformer, short-circuit proof" however looking at power supplies in my house that sign is not on many of them. There is a circle with a V inside no idea what that means!, a house which would seem to say it should be used in doors, a bin with a cross through it, which I assume means not to be put in the bin, the CE mark which I assumes means Chinese export! and the double square which means it does not require an earth the only sign I know what it means. However there is nothing to show the USB power supply isolates.
Now don't have an Iphone so can't look at Iphone charger, so thought I should select one which has come with a British product, the one I was looking at came with my Energenie MiHome hub, although hub made in England the power supply is made in China well know that it has CE mark.
As I go around the house this is repeated, the Yamaha supply is made in Japan so does not have CE mark, but other than that all seem to be the same, they do not claim to either isolate or be short circuit protected, well did find one with a mark showing it is fuse protected, but not isolation. Until this thread I had not looked, I assumed power supplies would isolate. I did find a Christmas decoration power supply with the isolation mark, but we all see the labels
but do we know what it means?