Runner on second base hit up middle rounds third to home. CF comes up throwing. Throw pulls catcher up line. Now I describe this as best I can. Catcher is fielding throw on chalk 3-4 ft up line. Runner does appear to veer towards fence to avoid contact. Catcher fields throw and tags runner on hip while still facing playing area. PU throws arm obstruction. Run scores. He says she must have possession to be in baseline. I say if she can tag her on front side on the play then she's out and legal play IMO. Judgment call so no cane raising but certainly didn't see same as ump. ASA