It may be accidental it may be not but we don't know because we don't have any pictures of the machine. But I'm more tending to beleive the OP because my friend had his MacBook and the palmrest was cracking. Is it the same as the screen, no but can it happn, I beleive so. At the fact of the issue is that the OP has been wasting his time and gas which btw Apple isn't paying him for to go back and forth between different stores. But I'm hopeful that his computer will come back fixed and working properly so the OP could put this ordeal behind him and move on.
Thank you Lozanjo, at least someone posts constructive comments
If you guys want pics I will post tomorrow as its 1AM here so need to get to bed
BTW what is OP?