Philip-

I likewise have never heard of such a thing.  I have de-primed thousands of
fired rounds of ammunition and have never given it a second thought.  It
sounds like you're not a reloader so let me drone on and excuse me if I'm
beating a dead horse.  A cartridge is de-primied with a die in a press.
The primer is removed with a decapping pin pressed against the inside of
the primer from the mouth of the case.  The pin is necessarily small to
pass through the flash hole of the case, 2-3 mm in diameter I'd guess.
When you have several hundred rounds to do, the process becomes quite
mechanical with no effort to be gentle with spent primers dropping out of
the case into a heap.  Some fellows use progressive presses so all the
various steps of the reloading process are done on a round before it is
removed or ejected from the press.  There are spent primers being driven
out, live primers being seated and powder being fed into the case from a
reservoir of a quarter kilo or so.  I cannot say with certainty that a
primer, live or dead, has never detonated during this process, but in the
litigious society of the US, if this was a concern we would have heard
about it and I haven't.  Reloading manuals and supplies would be covered
with warnings if available at all.

If it would make you rest easier you good give each spent round a dollop of
light oil, WD-40 or something similar to "kill" the primer and let them
stand a while before surgery.  It would be interesting to take a pile of
spent primers and chuck them in a fire to see if you could get a pop out of
them.  I'd be surprised if you could.

Phil