The code does exactly what it says it does, computer code is a set of instructions that the computer carries out - there are no secrets or backdoors - we have the code we can see exactly what it does. It really doesn't matter who wrote the first version of Bitcoin (Satoshi client) or who wrote the whitepaper - in fact, the original code has been more or less entirely rewritten now by the core developers.

There is very little evidence to suggest the NSA is behind it, and little motive, I could understand why the NSA would want to compromise something like bitcoin but I cannot see why they would want to start it. So it's just FUD.