Ipad temporarily sticks in landscape mode

Hi guys,

When I went into safari the display went into landscape mode for no reason and it stuck there until I killed the app and loaded it again, I did not have my iPad in rotation lock. I had a similar thing happen to Cash Of Clans, the display was stuck on as if the iPad is tilted to the right when I normally have it tilted to the left. Does anyone know why this has happened?

Thanks Josh