This is actually a genius idea (if implemented well).
Contrary to 'popular' wisdom, sometimes noobs pick up a bug that can be overlooked by those deeply involved in projects, etc.
The easiest way to cross-reference would be to build a libre[1] tool that analyzes sites like SO and uses some type of algorithm to identify possible bugs (then again, devs could already be doing this with special keywords they create on SO).
I can't build it myself, but maybe someone with some spare time and great technical skills can build this to improve the open-source eco-system.
[1] It should be free, as a lot of the work put in by folks is done for free (on their projects). If you'd like to charge for it somehow, then that is up to you.