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In your earlier post you stated that completing the TA position was required in order to complete the PhD program. My post stated that this is not the case, he could complete the PhD program without completing the TA position.
In order to fund his education, it was now up to him, no tuition covered as he was no longer a TA in the second semester. BK could have taken out student loans, I guess, and applied for federal funding for the second year, as well as student loans.
If he was establishing a state residency in Washington in order to be eligible for the in-state tuition for the TA, he would also be eligible for the in-state tuition in his second year as a doctoral student in Washington - even without the TA position. And he would be paying in-state tuition in his second year as a resident of the state. So no difference in tuition rate for his second year, if he established residency as he was apparently doing by changing his license, etc.
Edited to add - BK would be eligible for in-state tuition even without the TA position in his second year as a doctoral student at WSU, as long as he established his residency in Washington state per the requirements.