The google search required to find the answer ("federal statute for destruction of evidence") is shorter than your question here.
"Whoever knowingly alters, destroys, mutilates, conceals, covers up, falsifies, or makes a false entry..."[0]
If so, on that assumption, should no one ever be able to erase data on their hardware? Is it schrodingers guilt, that you're simply not guilty until someone looks, and then you are?
And if not, you haven't answered GP's question.
Legal cases are adjudicated by human judges who have been dealing with scenarios like this for thousands of years, since long before the invention of software and laptops, and who are not the least bit challenged when presented with strawman scenarios like the one you called out.
Did he know he was suspected of something? Was he suspected of something?
Edit: 18 U.S.C. § 1519 doesn't seem to cover this (unless it covers the act of setting up the duress PIN in the first place as "altering"). § 2232(a) covers actually knowingly providing the duress PIN.