I am unsure what caused the break. When looking at the pics I see one part of the metal that looks different. Maybe it cracked 20% before it failed. This truck has been driven hard. It has taken hits a lot harder than the ones on the day it broke. If spindles can bend then maybe the gradual bending/stress weakened it to the point a lessor bump caused the failure. Who knows. Just me guessing.
All I know is I am constantly breaking stuff and pushing the trucks harder and harder.
One the White Raptor I find that suspension bottoming out his not really an issue. Yes it will bottom and I am sure you can break it but for the roads/speeds I used to get beat up on in the stock setup I now just fly over. You can see the whoops in one of the links above. when I would run that road in a stock Raptor I would have to slow down or I was G'ing out on every whoop. The new LT setup just eats it up. The new limiting factor when driving is simply speed and road conditions (not whoops). If I am going too fast and the road is wet/snowy etc I will shoot off the road in a turn. So I find I have to speed check a lot more in areas of road where I can't see far enough ahead. In other words I can drive a lot faster with the LT suspension and the downside of that is I come into corners too hot at times and end up killing some shrubs.
But I am smiling all the way!
If you are keeping a stock setup but you are G'ing out a lot I would suggest getting the Outlaw Spindle gusset modification. I might also suggest going with an improved lower and upper A Arm. If you go with a new lower A Arm with hiem joints at the frame I would also look at adding a front air bump stop. I really think air bump stops lessen the hard hit on G outs for both front and rear. I also want Outlaw to develop some sort of weld on reinforcements for the lower A arm mounts on the frame. When I hit big rocks the mounts are pushed back. Obviously this impacts you alignment.