Part of it was going from tightening the crankarm on and then shifting to the chain.

And part was thinking the Park Tool was invincible and would just crush the chain (or squeeze the pin out like toothpaste) if it was lined up. It crushes itself.

Cassette's on. Left and right arms/chain ring is on. Old chain is still on, but the bike still functions. I just have to wait. And I need to figure out how to adjust the front derailleur since it won't shift far enough to the right to get the biggest sprocket. (I'm assuming a greased taper pin with the correct toque on the crankarm screw would push the crankarm as far as it's going to go.)