That does sound like an odd failure. I did have the roll pin that holds the frond drive shaft break, allowing the shaft to fall off the spline at that bracket. I guess it is possible that if the front axle was pulling hard when the shaft came off of the splines that it could put a good bit of force on that bracket.
I just saw your picture on your other post. WOW!!! Was there any rust in the breaks? Any chance you hit it on something solid? Looks like it is time for a new bracket, although I would look into having it welded.