The real issue is that the copper pipe may well have a full hot short, but
the
person is only getting a minor tingle because his shoes/socks are
moderately
good insulators, and dry concrete isn't that good a conductor either.

That begs the issue. It is only possible if the copper pipe is not grounded
(otherwise it would trip the breaker), but if it isn't grounded why would he
get a shock off the washing machine (or whatever machine it was)? The
chassis of the washing machine IS grounded, so you would trip the breaker
there also.

It must be that the copper pipe is somehow live, and neither it nor the
whole electrical system are grounded. It would seem like he would have to
know that somehow it that were the case. For instance, if my ground was
broken my dryer and overn wouldn't work. Something is going to be wrong.