The photo suggests that the actual fixing of the dropout to the chainstay tube is internal - the hole in the dropout is a clue - and that the crack is superficial.
Absolutely - the dropout is aluminium and has a longish post that is bonded into the end of the carbon tube. That's not a hole BTW, it's actually a reflection of something bright.
On the clean chain, I had probably just cleaned it, it may have been when I was replacing it that I noticed the crack.
I didn't think there was much point is taking it to a Specialized dealer; they would just do exactly the same as I did, which was to remove the wheel and give the dropout a good push and pull while listening for creaks. Then they would make some kind of meaningless statement that protected their own liability. In fact I did speak with a bloke at Specialized UK and he managed almost to agree with the carbon repair bloke's diagnosis of a "witness crack". He did say that he would be surprised if I ever had a failure because that was an extremely robust frame; maybe back in 2006/7 they were still over-building carbon frames a little.