Or if you're the military commander with the option to disobey the illegal order (to go to war without congressional authorization) or take the bribe and execute the order. "Unmarked cash" (which this is) has pretty different purposes from official funds.
I think there's a pretty good chance the person who took that money was opportunistic, this time, but $400k isn't a trivial sum of money, it's not impossible it was the difference between this happening and not.
It is if you are spending someone else’s $300 million, and getting the $400,000 yourself.