There is no possible way for that area to get damaged like that without leaving obvious damage elsewhere. I checked mine, there is no possible way for that spot to be stressed in any way to crack it like that, short of getting rear ended.
True story, reminds of a time way back in 87. I had an 85 5.0 Mustang GT. Factory ordered it myself back then so I could get the optional 3.08 gears.
Anyway, I didnt drive it much other than to the track and out of town trips and stuff like that. My friends brothers friend, a 16 year old kid just got a brand new 5.0 LX hatchback. Had it for a week or so. (This kids mother was also my mothers hairdresser).
They came to my door one day in a panic. He smacked it up against a curb doing burnouts or stuff like that and destroyed a wheel (same 15 inch alloys as mine). Knowing I didnt drive it all the time, they wanted to borrow one of my wheels so his parents wouldn't find out. No problem and we did just that.
Unknown to me, I found out a few weeks later that he brought it to the dealer to complain it pulled to one side. He did bend something in the front suspension. The knew what happened and just couldn't figure out how he did it without destroying a wheel.
Anyway they fixed it all
UNDER WARRANTY. (except the wheel of course, he got that ordered through another buddies shop)
Funny I also heard he was pissed (not at me just situational) because, since I remove my wheels to clean the insides (like I still do), he ended having to do the same to make it look convincing enough with all 4 clean wheels.