Originally Posted by
SquidPuppet
The high pressure seeks the path of least resistance. Over time it pushes the "least well" seated part of the bead away from the rim enough to sneak past it and bursts, like a pinch flat from a bad install. That answers why it happens in random different locations on the same rim. A theory. Nothing more.
Nope, a burst outside the rim/tire confines results in a large split or a star-shaped hole from explosive release, and the paired dimples is still unexplained.