Not saying it's not possible that OP's filter was indeed damaged during use, but as a general observation/question: I think it's certainly likely that 1. some of these filters do have brittle media, and 2. when people (in general, not directed at OP) start fingering pleats looking for tears, actually create some of them. 53' Stude, you cut the highest number here on the board that I know of- have you been able to tear media by pulling pleats apart? The failures I believe without question are the ones where they are visible without moving/stretching/pulling the media around to look for issues.
OP, thanks for pics. Always good to see a variety of filters cut!