[renowner]

I really hope this is a bug, and not just an intended mechanic.
I would hope that this is just a holdover from how lightning crits never used your weapon's crit or crit multiplier. Which made sense for those skills, as they have other ways of being buffed, and did full scaling and full elemental attack.

For the other weapons, twin shot included, I would hope that the weapon's base crit multiplier does count, unless that would somehow be just too overpowered.