I had a set of Araya wheels with narrow (700c x20) hooked rims and high pressure (150psi max) Continental clincher tires.
I installed them on a road bike, and took a test ride. I did not get far and the tire started to roll off the rear rim.

Remarkably, I was able to remove the tire without any tools (normally I can't do this). I inspected and no problems were apparent. I assumed it had been under-inflated.
Then I reinstalled it, reinflated to 140PSI, and took a second ride....

I started out OK, but then the inner tube blew with a loud "pop", and wrapped itself around my rear brake and axle.

I walked back, untangled the inner tube, and indexing the torn section to the presta valve hole, I checked for any bit of glass: None found -but THIS time, I noticed a slight low spot in the hooked rim - one not immediately apparent to the eye, but one you can most certainly FEEL.

On consideration, I suspect THIS was the reason for the blow-out - though I have NEVER experienced such a thing with any other tire!
(Even cheap, six-dollar 27x1" tires from Niagara will stay on with a big-old-huge-honking dent in an unhooked rim.)

So what I need to know is this:

Is it because all skinny high pressure tires are immeasurably more sensitive to such things?
- or is it because CONTINENTAL high pressure tires are more sensitive to such things?