JMO but I think he had his crime all meticulously planned out (and probably it went badly wrong in the house) -but- disposing of all his clothing, the plastic sheeting, the knife, having a wash down etc was something he'd rehearsed. He'd probably figured out a location, left his fresh clothes in a bag there so they'd not even be cross contaminated. I think he probably burned his things, used an accelerant, had a little fire, maybe then tossed everything in a lake or river. That knife? Where could it be? How far could he get in those 17 minutes?
My personal guess is that he got rid of most crime related stuff ( probably including the knife) the day after. That 15 mins of extra time before phone goes on and pings off Blaine tower, could have been taken up driving an off road route between Palouse and highway 95 south of Moscow.
My conjecture is he went west when emerging onto Palouse from Conestoga ( time approx 4.20-4.22am) then took a left at Snow road and doubled back to highway 95. At that point he feels safe enough to turn his phone back on and the time is now approx 4.48am. His phone pings off Blaine tower. Just my speculation.
This way he avoids cameras at intersection of 95 and Palouse and also the business cams in that area. My theory is that he was familiar with the Snow Road option for his exit out of Moscow area and knew the road well.
Also, on the way to Moscow that morning to commit the crime, where phone suddenly stops reporting in Pullman at approx 2.50am, my theory is he switched off and then took a north-easterly route ( north of Moscow -Pullman Rd) to emerge on highway north of Moscow. He then traversed various back roads south to end up on Indian Hills drive at approx 3.26am ( first camera capture).
All above is based on approx times and locations in the PCA. Ditto for speculation below.
During daylight afternoon hours on Sunday 13th Nov, BK was near Snake River south (when he visited Albertsons). Maybe the knife disappeared into it. Or also during darkness between 5.30pm and 8.30pm that night, BK's phone stops connecting for three hours, in the vicinity of Johnston, WA. This is a vast rural area, part of which BK traversed in darkness earlier that day on his route back to Pullman post crime.
Three hours is a lot if time to deal with crime related stuff, maybe even an initial car clean. Moo. Just a few ideas that pop into my head now and then.