Can Flashing the memory fix a broken touch screen?

So heres the deal. My touchscreen started acting up and was almost unusable. The bottom half of the screen often didnt regester my imput or oddly enough it would be triggered if my finder was like half an inch away. I tried everything I could think of but eventuall I rooted the phone because I thought I could try putting a new rom on it to fix the problem with my touch screen.
Eventauall I got to flashing the memory with CWM and it worked right away and I can't figure out why. Anyone understand what's going on here?