The riskiest play in ultimate is not the huck. People assume it is, but the fact is that if you're comfortable with a long throw and if your guy is open - and these are, of course, two prerequisites for throwing a huck - then there isn't an issue. Fake break side, wind back, step out, and put that shit up. It's not an issue.
The riskiest play in ultimate is the up-line cut - the money cut - and it goes like this. The disc is trapped on or near the line, and the dump - on stall four to six, maybe - takes a step towards the around and then busts up into the force lane diagonal to whomever has the disc.
And the throw isn't hard just because hitting someone running nearly straight away from you is tricky - it's hard because at the moment you have to let go - at the moment of release - your mark is in between you and your target. You get to see him and his defender a second before you make the throw, but for the most part you're blind. You watch the first two seconds of a five second race and have to decide who is going to win. You don't know what's on the other side - your handler could have tripped or it just could have been a fake. This has happened before - we've all seen it happen, that the disc is trapped on the line and then it gets thrown five yards up to no one because the dump changed his mind.
Worse still is that the money cut is a bailout throw - if you don't hit your money cut then you're on stall seven with a defender right in front of you in the lane and no dump at all. New players look off the up-line because it's scary and then end up getting stalled. Or maybe even the handler - a senior, the friendly and athletic captain of the team - shouldn't have made the cut. His man is tight on him and you don't know how much space he has.
So you put it up, maybe, high and sort of far because his defender has already laid out for a few d's, and he catches it and immediately throws a huck to a continuation deep. Or you don't, because, you know, sometimes you don't. The first player in the stack knows what he's doing, and you've always trusted your break throws. It might be worth a shot.