Nope...never! The issue is that if you start swapping the ground and neutral you make the ground wire a current conductor and can have parts of an electrical system energized that should not be.

We may only tie the ground and neutral together in the panel and nowhere else in the whole electrical system.

The ground conductor is normally never a current conductor (except for slight leakage). Ground and neutral are both grounded conductors that perform different jobs in an electrical system.

I've been on commercial/industrial service trucks where I've seen a lot of shady stuff with grounding, though.

Live supplies the electricity.

Neutral returns the electrical path to ground and is a grounded conductor. It completes the circuit.

The earth or "grounding conductor" is another grounded conductor that normally doesn't carry any significant current (except perhaps a small bit of leakage). It's there for safety so that if there is a ground fault that the circuit breaker can trip (or fuse blown). The metal chassis of an appliance will be tied to earth for safety reasons.

The earth and neutral are tied together at the panel and nowhere else.