As supporting evidence, here's a couple WWS links from our first and second week killing Shadow Twin first:
First week:
Shadow Image - WWS
Zero attacks any either of the two tanks or the three people in melee (Bazz, Mokokomass, Punkrocker, Thelastrace, Barrelroll).
Second week:
Shadow Image - WWS
A little bit more, but all explainable. Oark had a shadow image get on him while he was running out for a conflag. One shadowfury hits Hardcore, Barrelroll, Enervatex, Bazz. Mokokomass and Punkrocker again take zero hits from Shadow Images.