That bug is not uncommon on OS X, it happens with a few of the drivers. (mostly seen on the nVidia 8xxx and 9xxx series?) And it is not that they are not cleare

That bug is not uncommon on OS X, it happens with a few of the drivers. (mostly seen on the nVidia 8xxx and 9xxx series?) And it is not that they are not cleared, it more often than not is things that should actually be in memory But for some unknown reason, the driver maps memory the wrong way and poof you get the wrong texture, sometimes they are garbled sometimes not and sometimes hilarious results (was referred to as the 'Avril Lavigne issue' in the EVE community for a while.) I would say it is an issue, but it is not a very serious one by current WebGL standards, there is not any controlled way of getting random textures of your bank account etc, there are probably worse issues with 3D graphics drivers than this.