Still, if the neutral is broken at the transformer, you still don't have a
return path.


You have a lot of confidence in your position, so I think an experiment
is in order, to verify the conclusion. First, go up the power pole and
snip the neutral at the transformer. Then, go down in your basement,
open up the main panel, put a finger on either one of the hot buses, and
then grab a nearby copper or steel water pipe with your other hand. If
we don't hear from you again, then we'll conclude that there can indeed
be current without the neutral at the transformer. Otherwise, please
report your findings.

All seriousness aside, if there's power on either of the hot legs, then
you don't need a "return path." Even when it's connected properly, the
neutral is grounded, anyway, so the "return path" is from hot to ground
-- any old ground will work, and that's why it's a potentially dangerous
situation.