Mine was a seam detachment, outside of the "O" ring, where it attaches to the outer casing. It was just a lot of drips, not a forceful flow. Enough to mess my driveway up.
I hate getting oil on the driveway as it's so hard to clean up. Personally I've never had a oil filter separate like that. I've had them crush but that was because of the clown who installed it put it on way to tight.