The evidence is starting to add up. First, we have the absence of evidence, which is always tricky but sometimes relevant: Nobody picked up a rocket on radar, aircraft pilots did not see a vertical high speed accelerating object, etc. etc. Then we have the alternative explanations, including the shape and nature of the contrail, curves in the contrail unlikely from a ballistic missile, and so on.
I’m betting on routine aircraft contrail. This will be an interesting one to pick apart later when all the conjectures are in.