WC,
It looks pretty clear that the trans was forced into the disc. Look at the extra, small tooth imprints in the leading edges of the teeth. The force used to push the trans into place created the input shaft spline imprints in the disc hub, pushed on the F/W side drive plate cracking and distorting it, dislodging the hub damper plate as evidenced by the spring location tabs not being centered in the 4 notches in the drive plate and one of two possible things might have cracked the hub itself. Either the force used to pull the trans into the disc was enough to cause the crack OR the trans was hung partially in the disc and the weight of the trans cracked the hub.
I have a small collection of "warranty" discs at work that have had their trans pulled in with enough force to do the same damage as you have. I wasn't there to see the install, but one possible tool that does it is longer bolts being used to PULL the trans into position, it means trouble no matter how you slice it. Discs must be centered with the alignment tool and the trans must be carefully guided into position with skill and patience. One thing we do in an install is to try to rotate the trans output shaft (in gear) while getting the trans started in the teeth. Also, it varies with skill level and experience and luck but many times I pull the X-fer case off and just stab the trans alone, makes a smaller easier to handle package. I stress reading the "gap" between the back of the engine and front face of the trans and actually sighting down the trans case holes to find the mating holes in the engine adapter.
The stop pins are the double headed rivets that secure the damper package. They are visible from the edge of the damper and the hub flange rotation is limited as its notches hit the stop pins. IF the stop pins are beat up, the engine had a lot more torque than the damper had spring rate to keep the flanges from hitting the pins. If the pins show no wear or witness marks, then the damper had a higher torque capacity than the torque that it saw. But if the damper had been severely damaged from running off center due to an alignment issue, the damper can't float its always loaded and the stop pins see more wear.
If this clutch did not slip under load (prior to current failed state) on a good uphill pull with a load, then the system had more torque capacity than the engine had torque. The resulting facing wear is then most likely resulting from driver actions OR contamination at assy from not cleaning all of the casting surfaces, BUT I think that would have showed up a lot sooner.
No matter who's clutch a major amount of the success of the clutch is in the attention to detail during install and the skill and experience of the installer. Also my comments were solely based on the pictures submitted, not a hands on inspection.
WC, want to check one other installation detail? Take a look at the old release bearing collar bore, is the bore of the collar nicely greased, or dry and nasty?
Gary
Attention: TDR Forum Junkies 
The trans input shaft was ok though.
