It is not really all that confusing even for people unable to research further than reading Wikipedia. The margin in favor of the Republican was far greater on election night. Somehow more and more votes kept turning up from urban areas in Western Washington in the days following the election. There should be newspaper articles from the time period available online to confirm this timeline if you want to research further.
But please do not worry yourself. I understand that you do not find any significance in the election that was stolen here.