Hello, I tried removing my iPad Air from the apple smart case and had a hard time - as I was trying to remove it, I noticed a rippling effect on the display (I was applying pressure to the back of the ipad to pop it out of the case). I was able to get the case off, and the device seems to be fine now, but is it possible my screen is going to be damaged now? How durable is the glass covering ? I also find it strange how much force is required to actually free the device from the case. Thanks!