Its not a coverup. It is the purposeful use of ambiguous information to suit ones purposes. Arguing that Obama didnt downplay this would make you the most naive person in the world. Seriously. He was running for the most powerful position a human being can have. He is as corrupt and compromised as any other national-level politician.
If you think for even a second that his ambiguity in the face of the truth wasnt a calculated move... I just dont know what to tell you.