maybe the problem was the very hard ground under the relatively soft snow?

 

ok let's see if I can explain it.
I don't know for sure if it was the peg (floor board actually) that caught, or maybe just the tires or what. where the bike caught and stood up and then came down on left side, snow was about 4 or 5 five inches deep, where our slide started was about 18 ".
But regardless somehow the bike dug in and stopped sliding, but the momentum lifted the bike up and over.
When it came over that's when the majority of the damage happened.
The new thin plastic HD uses shattered. Partly because it is so thin and possibly because it was cold that day (40's or so).
It is possible when it went over to the left side it rolled enough to strike the trunk on the top edge thus breaking it and tweaking the mounting tube, or maybe it was just the snow in the area, that it pushed up like a snow plow I don't know. but it did not slide on left side, so don't know for sure how that happened.