Well, let me tell you this. My friend's cousin who came to the US in 2003, got out of status for couple of years, reinstated in 2005 and then got out of status in 2009 and reinstated in 2012 and now talking a walk in 2015 May, his parents got visa last week and coming for his graduation. It will be a grand reunite after so many years.
So, its not always the case.

On the side note, even though they didn't open the file in front of your parents, they must have already gone through all the documents submitted while your parents were waiting.
So, something is wrong either in documents or your record.