Having "full confidence" and "knowing it was all over" are two vastly different things.
If I had to jump off a 2nd floor balcony to escape a fire, I wouldn't have full confidence I wouldn't get hurt, but I also wouldn't think that I'd die.
One thing that was point out in the pilot breakdown from earlier, they were past the point of no return. I'm not sure how far past the retaining wall they were thinking about/ able to see, but they cleared it and it almost seemed like they were in the clear.
Do you think that hitting those powerlines was the proverbial straw that sealed their fate?
Already missing one engine, carrying a full load, full of gas. It looked like that took all their momentum away to me.