Seeing pink wards with no pinks in the area

idk what it was but i was playing vi on (greedynublet) and was jungling her, when i went to bot lane to gank when i went into their tri bush (with no wards at all in the surrounding area) saw their pink and janna was no where near to freshly place this ward...so i killed it. later at dragon same thing happened there was no wards in the surrounding area and i could clearly see the pink outside dragons den. almost the same range as if i had an oricles on me. now i didnt see if leona had wards or not but they were duo on bot so maybe they didnt need them but the wards could have been there and i was gltiched and could not see said friendly wards or i had a gltiched oricles ontop of me that was invis.