Only thing I can think is that, with Benghazi emails coming out, Trump is giving Obama one more thing to deal with.
Obama will never release his records.
Trump gives 10/31/12 deadline. Obama will not release records and will get contrary with Trump. Maybe some people will change their minds on Obama on election day only a few days off.
Obama will look poorly with his non-release and Trump will needle him with a thousand cuts.
5 million bucks? Why not just forge something?