The split on mine was at the top, inside the clamp, next to the base. I know I caught it before I sucked anything in, but since then I check it a couple of times a week just to be safe. I put a "shim" piece of foam under the filter to provide extra support. As you know, you can move the filter up and down some, so there is probably some vibration movement while running and therefore, stress.
aFe was very responsive and concerned. I sent the damaged filter back to them. Got a free t-shirt in the box with the new replacement.