PBL:
Well, I accept that you don't see one. But that's the thing with these matters. No one saw a problem at Cali, either. Neither did anyone see a problem with having another NDB with the same ID and FREQ 200nm east. I mean, why would you ever tune it in from so high up? But they did.
Those guys were both "radar babies" and "children of the magenta line."
First, they tried to get a short-cut in to a procedure in a mountainous area in a non-radar environment, and in South America no less. That flunks IFR Flying 101 right there.
Second, when the aircraft started its big wild-a** turn to try to go to the wrong beacon, a passing grade in IFR Flying 101 would required disconnecting LNAV and using the heading mode to get back on track
now. Instead, they became passengers, continuing a wild spoiler-aided descent while letting mis-programmed LNAV take them to neverland.
It was a ground-based combined arrival/IAP procedure they were attempting to fly with RNAV. For those with clues in 1995, there would have been more than a modicum of wariness.