I'm learning now Horayos, and it seems to me that Rashi there is somewhat different. Too verbose, I would say. Are there any sources that in Horayos Rashi is indeed Rashi, or it is not?
When I learned a few of the Dapim in Horayos almost a couple years ago, my Chavrusa told me that according to some opinions, the commentary attributed to Rashi was not written by him. Therefore, it is not called Rashi, and is instead called Mefareish.
Cf: Rashi in Horayos