Weird iPad screen glitch

Hi
Just now I got a few drops of water on my iPad screen, so I rubbed them off. As I did, the home screen was responding and switching between app pages. It then froze in between to pages, all the water was cleaned off and I made sure none got in anywhere. I then tried pressing the home screen to unfreeze it and nothing happened (it has never frozen until now) so i tried touching it for ages but it remained frozen. I then put my smart cover on and off and then it unfroze as if nothing had happened. Has this ever happened to anyone and do you think there was still some water residue that may have caused it?