It doesn't matter. They threatened him with it. They didn't threaten this DEA goon with it. His union lawyers or whatever made sure of it. It was real to Aaron.
Even if that's true (for which no evidence is presented), the DEA agent, being a federal law enforcement professional, probably understands federal sentencing, so probably wouldn't be susceptible to threats that can only work on someone who doesn't understand that.
> His union lawyers or whatever made sure of it.
I am sure that any competent criminal defense lawyer makes both the theoretical maximum and the likely real sentences clear to their clients, yes. That's actually a good thing, I would say. Not, of course, that information on this is particularly hard to find even for reasonably intelligent laypersons with access to public information.
And no, Aaron was definitely not "threatened" with 50 years. Where are you getting that from?
Force faced a cumulative maximum sentence of sixty years and $750k in fines. He opted to plead guilty. There's no particular reason to believe the plea bargaining process was friendly. He got six years, and the prosecution argued for more.