A sad case of automation confusing the civilian crew
Lockstock, the automation didn't confuse them. What confused them was the fact that they didn't plan their initial approach, they then accepted the offer of a shorter approach without giving adequate time to consider whether it was a good option or not. The PNF(Capt) entered a new (incorrect)waypoint in the FMS without checking it's Lat/Long or asking the PF to confirm his selection. The new course line, which gave them a sharp left turn, wasn't checked and confirmed. They didn't pick up on this turn initially, but when they did and turn back towards the airport, they didn't realise that they'd crossed into a different valley. They didn't follow the approach plate. They asked to cut short the published approach. They didn't recognise the ident of a beacon, because they hadn't briefed the approach. They started their descent without passing over a specific beacon.
Yes, they were confused, but not by any automation.