I've heard all the web rumors about Fram filters and most of them are along the lines of what Ben described above, crimp failure. In my decades of off road jeeps and sand rails I've been first hand eye witness to about 10 such failures. Only 1 was a Fram.
I'm convinced the genesis of the rumors is simply due to the large market share enjoyed by Fram, more units in use should lead to more failures but not necessarily because of quality. Of the 10 I've seen first hand 7 of them definitely showed evidence of an impact of some sort. Two Wix and one Motorcraft showed no obvious reason for the crimp failure.
Considering the filter is about the weakest thing on any wheeler there's no excuse leaving the road without a spare IMO. I've helped 5 guys over the years self rescue with my spare and have never needed it myself.