QA (no &) testing usually doesn't have much in common with actually playing a game. Even when playtesting you are often focusing on a particular area, class, race or skill inside the game. The job varies from company to company, with some placing more emphasis on checklists and others on playtesting.
I really think some internal Obsidian testers who didn't work for Lucasarts would contribute to the project. I say that entirely out of self-interest and ambition. Can you *really* trust 'em? They work for the Man.
*ssshh* Not so loud! They have agents eveywhere!
"The Man" pays the bills...