When installing GFCI outlets on ungrounded circuits today, the
electrician fitted each with a jumper between ground and neutral. I
told him I'd thought I'd read that this was a bad thing but he insisted
that it was the correct way to wire an ungrounded GFCI, that he does
this all the time, and that if I doubted him, to ask the city
inspector.

He did not label the GFCI outlets as "no equipment ground", which also
seems like a no-no.

Am I right that this is bad? Is it bad only in the case of a miswired
circuit? I can find one or two web sites that say it is bad but
"someone said so on a web page" does not make a persuasive argument,
and if it is unsafe, I'd rather have it fixed than wait and raise it
with the inspector. Can anyone point to an authoritative description
of why this is bad? I can see it is a problem for a miswired circuit
with hot and neutral swapped. Are there other scenarios where it is
dangerous or might increase reliance on the GFCI tripping correctly?

Based on my limited understanding of GFCI operation, with the jumper,
if an appliance case were to become energized, current would
immediately flow through the ground terminal, through the jumper to the
neutral return, bypassing the GFCI transformer and tripping the GFCI.
Without the jumper, energizing the case wouldn't produce a current
until (say) my body creates an alternate path to ground. The first
scenario actually seems marginally better?

-- Dave