Originally Posted by
power5 Appears to be an OS responsiveness to me. Not something that bothers me too much since it doesn't affect me most of the time on any of the phones I have used. iOS3, WP7.5, or Android 4 all have some unresponsiveness at times. Will not allow swiping till it resets after the close. Open a few more apps and then try to rapidly close them one after another before the animation is done. Just like you are doing with the swiping, try it with closing more apps.
That said, it's only annoying because you are trying to do stuff so fast. Yes it's likely an issue with the OS and until another video comes up showing a contradiction, we will have to assume that as the case, or hardware. But considering you touch the same exact spot on the touchscreen multiple times, I doubt it's the digitizer.
Also why no make a video of your z30 if you still have it to show the difference?