I always thought this was rather called a 'Heisenbug'?

I think the distinction the author is making is that:

- a Heisenbug is stochastic and potentially non-local, but

- a Higgs-Bugson is a bug that is known to exist (in prod) but is extremely hard to observe in the lab (during dev/testing).

I can see it being a useful distinction. A bug that I can't even reproduce at all sits in a different ring of hell from, say, a memory corruption bug that makes the program crash on random unrelated lines of code.