Wayne Watson wrote:
"The voltage returns down the line, and the current does not."

What happens on reflection is that either the phase of the current is
reversed with an open circuit, or the phase of the voltage is reversed
with a short circuit, in the event of a complete reflection from an open
or a short. In either case, there is a reversal in phase of only one of
the components of the electromagnetic wave, not both. However, the total
wave is reflected.

A transverse electromagnetic wave consists of two components, an
electric field and a magnetic field. An incident wave has both parts
in-phase until it is reflected.

A reflected wave has its two parts 180-degrees out-of-phase upon its
first reflection. This fact is how the directional coupler in the Bird
Wattmeter distinguishes between the waves traveling in opposite
directions through the wattmeter.

Both voltage and current return upon reflection. The difference is zero
phase difference in one direction, and 180-degrees difference in the
opposite direction.

Best regards, Richard Harrison, KB5WZI