^ Yeah, the problem was that he wasn't allowed to write his own script. I guess they wanted to be sure that the speaker wasn't swearing in his own language (probably more of a concern for the modern languages, though). So there are translation errors in the game even though every speaker is either someone who is a native speaker or studies the language thoroughly (when, obviously, there is no native speaker).
As a born and raised Seattleite, I am curious... do you have any references? I always thought my accent in general was a fairly mild but standard American accent. Our vowels aren't as flat as the midwest, and I know I pronounce a bag, bagel, roof, and a few other words differently...but I wonder what the overal defining parameters of the accent would be. I recall an English poster here saying I sounded Irish, which I thought was odd.
I had a link about three years ago. I'm trying to find the sources I had (I did a quick search of the board to see if I posted it previously. I see that you apparently asked me back then and I missed it, so my apologies. I think I never posted it). Some appear to have been dead. It's essentially developing the characteristics of a different accent when compared to the California or West Coast accent. It strikes me as something a linguist would notice more than the average person. Most people think they don't have an accent if it's subtle.
Here are the best links I can find. I don't remember if any of them are the original story I read.
Is There a Seattle Accent?
A blog that has a dead link to the Seattle PI that might have been very helpful if it still existed
A Northwest Dialect? That's Goofy Some Say
Sorry, that's the best I can do. I get the impression that, while it's being studied at the University of Washington, the study is still in its infancy.