I do remember that Shagrat seemed to know many things about how Shelob hunted her prey, so I think its reasonable to assume he at least watched her from afar, so I'll accept it. I was actually thinking the same as you except replace Shagrat with Gollum. Gollum at some point mentions that Sauron was missing a finger so he must have been in Sauron's presence.
Good job

The thread is yours.