Jen, palpatine used force lightning on yoda after killing mace... plus luke was only supposed to defeat his father, not go directly after the emperor... and maybe blocking force lightning wasn't part of the necessary training to be a jedi.

WARK!

Thus Spoketh Winterclaw: a blog about a Winterclaw who speaks from time to time.

 

(using Poser Pro 2014 SR3, on 64 bit Win 7, poser units are inches.)