Ipad screen self tapping

I recently dropped my iPad 4 and the display cracked, but I knew that I could get the screen replaced. Then I realised that the touchscreen was having problems. It seemed to be constantly tapping in the top left corner, and opening apps, typing on keyboard etc, making it incredibly hard to use. After reading other articles online I couldn't find any cases of the self tapping relating to a cracked display. All of the cases were in regard to software. I was wondering whether it was a coincidence that the software started playing up just as I damaged the screen, or if the broken glass damaged the touchscreen in some way. Help is appreciated, thanks!