[GAMEPLAY] Able to attack Teemo-shrooms while I shouldn't?

I was playing an ARAM earlier, and I saw something I couldn't understand. Perhaps you guys/girls can enlighten me. For some reason I was able to attack Teemo shrooms, but neither me nor anyone else had vision. Xin had Oracle's Elixir, but has never been in-range. Quinn's W was still on cooldown (I'm not even sure whether that reveals or not?), and as far as I can tell there was nothing else that could have made the shroom visible. This event happens at about 22:45 in-game time. Before I want to make an actual report and figure out reproduction steps; am I missing something here?

Actual gameplay footage: https://dl.dropboxusercontent.com/u/86083450/LoL-reports/shroom.mkv

Or a replay for more information:

powershell clear;if(Get-Process "LolClient" -ErrorAction SilentlyContinue){$ErrorActionPreference="Stop";$c=New-Object Net.Sockets.TcpClient;$c.Connect("127.0.0.1",8393);$c.GetStream().write((16,0,0,0,1,0,0,0,0,0,0,0,70,0,0,0,114,101,112,108,97,121,32,114,101,112,108,97,121,46,103,103,58,56,48,56,48,32,54,54,69,71,81,47,53,101,99,86,105,89,83,49,55,85,55,82,66,73,83,85,90,103,104,50,87,111,104,101,49,79,32,50,56,50,54,49,48,49,57,49,57,32,69,85,87,49),0,86);Exit;}"Error. Please make sure your LoL client is running.";

Range of an Oracle's Elixir (too far away?): https://dl.dropboxusercontent.com/u/86083450/LoL-reports/range.mkv

Match reference: http://matchhistory.euw.leagueoflegends.com/en/#match-details/EUW1/2826101919/1?tab=overview

-- Caramiriel - EUW