But in reality, if he (or his parents) wanted to, they could (with a competent attorney...), approach the FBI about cutting some kind of deal that could take many forms (not prosecuting lying to the FBI, not being prosecuted for or having to admit they lied or fled/assisted fleeing the law, millions of possibilities) in exchange for coming in with with their attorney and/or providing information about what happened.
Truly, these kinds of arrangements happen all the time. The best way to torpedo any future negotiated resolution/ leniency/ compromise is to keep jerking LE around, wasting time, money, reputation of the various agencies involved.