Bug: Mini map shows vision of an area, when team has no vision

As requested by riot support, posting bug report on forums

I have attached a couple screen shots of the bug

What to look at in photo: bot lane tribush and part of top lane (in the photo at 18:00) same areas as before but bottom side of bot river as well plus part of mid lane (in the photo at 19:50) same areas as before as well as a part of botlane near the outermost tower that is still standing (in the photo at 20:40)

Client: Mac

Bug: Mini map shows a place as illuminated (illuminated as in showing that you have vision of the area) even tho you don't and stays that way the entire game. It will not tho show any enemies inside the area that looks like you have vision. This can be extremely frustrating as well as give you a false sense of security at times.

How i think it happens: I noticed that when my game crashed for whatever reason, if i had vision of that area from a ward, that then dies before i get back, then the mini map will have the aforementioned bug.Then after this initial crash and the initiation of the bug, a couple of the wards i placed later on, when they died created the same bug in those areas. This can be seen in the pictures. I'm not 100% thats how it happens, but I'm pretty confident.