I vaguely know a guy from here in Winnipeg who's in a guatamalen (or is it in venezuela? can't remember) jail for trying to smuggle coke home. He claimed it was planted by others too, and his parents were in the paper demanding he be released and everything except months later some of his friends admitted (to each other at least) that he had talked about making some money while there by carrying some shit back before he left. He was there travelling with his brother and a few friends but only he got caught.
He was a normal guy without a record or hardcore criminal friends or anything beyond some stoner buddies - since then every time I read about cases like that no matter how 'innocent' I think they sound I assume it's a 50/50 call on whether they were muling or just got fucked over. He got 20 years or so too, in a truly godforsaken prison somewhere.