Right, no taxes paid anywhere yet. And like many other states, WA wants the difference between what you have paid elsewhere and what's due in WA.
I could ask a doc agent, and a number of people have suggested various attorneys. My feeling is that if I need an attorney to visit a state, that's all the reason I need to not visit. And if the DOR can't give a consistent answer, I'm not sure what value a doc agent's view would be since at the end of the day it's the DOR who I'd be fighting.
Your scenario is one of the straight forward ones. Were it gets complicated is when you come and go over the course of multiple years, crossing the 365 day boundary, use your 60 visitor days, repair affidavits, and visitor extension permits. The interaction between all those allowances is the thing of nightmares. People can't even agree whether the various permits run for 60 consecutive calendar days, or 60 days of use in Washington, i.e. the clock stops if you leave the state. The state treats the first 60 days one way, and the renewal permits the other way. It makes a big difference. The the actual language in the law is the same for both permits, so you would expect them to operate the same way. But the DOR doesn't, yet a friend got a binding determination from the DOR that directly contradicted what everyone else at DOR has told me and others.
And does the clock stop on any of those permits when you enter into a repair affidavit? The answer would appear to be different for the different permits, but yet another friend got a binding determination that said the opposite.
The bottom line is that I can't confidently comply with the rules, and with 10% at stake, I have no choice but to vamoose.