I don't have conspiracy theorist leanings. But whatever it was, it definitely looked "structured". It's very curious is all I'm willing to venture. That said, I don't think there is any possibility it's "alien". Man made? Yes. Alien? No. Cosmic ray or some such artifact? I guess we'll find out when they do another pass, whenever that is.
But...if it is man made (and therefore "secret"), don't you think it would be edited out of any future access? I tend to think it would have already been edited out, but who's to say it wasn't another government and ours didn't know? It wouldn't be the first time something sensitive showed up on these "google maps" tools.