That's what you get for listening to crappy music...
A nickel sack would be about $5, or a gram of marijuana, which is an absurdly miniscule amount. In Idaho possession with intent to distribute, which this would presumably fall under, provides for up to five years or a maximum $15,000 fine for less than 1 lb. or 25 plants.
The men were not charged with any crime, so presumably their story checked out. But, perhaps the funniest takeaway here, aside from the joke that is our criminalization of marijuana and the waste of time and resources we spend policing it, is that to be on the safe side, we had better all just stop talking about Nickelback altogether, joking or otherwise, just to be safe.