I'm not sure that we are talking about the same issue. I've found a bit of confusion on this around forums. L1520 has two different flaws, one is the touch screen interpreting a scroll like a tap (or a tap as a double tap, that is the same, as appears that the CPU has some kind of throttling that make the data flow coming from touch screen intermittent). I used to have the same problem on my L920 using TVshow app, but only in that app, that makes me think that is software related. Also, if you power cycle the phone, usually the tap/scroll issue is gone for a while, and that points to the thesis of software/firmware related issue.
On the other hand, many people are complaining about another issue, that I had myself on 2 different 1520, that is related to navigation buttons, where you experience Cortana (or Bing search) popping out by itself, multitasking showing and shaking like crazy, often related to top left corner of touch screen acting like the back button. This has nothing to do with phantom tap issue, it's hardware related, and can be solved only opening the phone and tightening the screws placed on the motherboard, as the problem is caused by esd contacts not touching properly the metal plate behind the mo.bo. Someone suggested the bending trick, but unless you tighten the screws, it will come back. So, end of story, I really think that phantom tap can be fixed via firmware update.