That's not how it works: you start with the null hypothesis and you try to see if you can reject that with some confidence interval. In this case, the null hypothesis is that it's some kind of ordinary object, and its path is determined by gravity, radiation pressure, and outgassing. Only if you can demonstrate why this is highly improbable can you start talking about alien probes.

As others have argued in this thread, once you do this kind of analysis there's nothing left that is odd and needs explaining.