The Answer: Does Lightning Strike Down or Up ?

Apparently, it's a bit nuanced...

In some cases it's clearly going up - originating from the top of a tower for example.

In others, the sky is striking downward but the ground's charge reaches up to meet it,
and when the two connect, the side with the positive charge blasts along the "circuit" to
the negative side.

Very well explained (and shown) in this 4 minute video...