I agree with Clarrie and somewhereat1, he should be court ordered to pay back the full amount to VA, the 21K+.
That will ensure he learns his lesson for this incredible stupidity.
In the USA at all security cx points it clearly states making any security related/bomb jokes is an offence and will be treated as such.
Doing so in flight would probably have caused the flight to return asap and he would have been arrested and charged. The damages/loss bill would have then been a lot higher to say the least.