clairvoyance summoner spell bug

I saw that clairvoyance would randomly go off in the middle of the game. I saw it happen two times the first time idk could have been from my team i didn't think much of it. but the second time i noticed it when i was dead and clairvoyance went off on a enemy turret that i was looking at little while before. though i did not use it and i was the only one on either team that was using clairvoyance. this happened on Ezreal both times he was also using an AP build. {{summoner:2}}