One doesn't necessarily mean the other. They could have mopped, dusted, waxed, and cleaned the toilets in there, but didn't get all MK's DNA traces off the machine before starting again.
It's funny because I was reading an article about this case that said false assumptions on the premise (ie, the breakin being staged) led to more false assumptions (ie only AK could have done it) which led to more false assumptions (AK is the murder) which led to a false conclusion.
Same thing for PL. False assumption on what "See you later" meant for Americans led to false assumption that PL was involved. That led to a rigorous interrogation, where AK was hammered because the police "just knew" her and PL did this with RS. If they are under that belief because of the false premise, they will accept nothing from AK but agreement with it. Thus, she finally starts agreeing with it, which leads to his arrest.
I'm just saying these things because we have to be careful in our assumptions, make it known they're assumptions, be willing to be corrected if we're wrong, and basically stick with the facts and whether the facts bear out these assumptions.