Man, that hurts, I am sorry for you!!
I lost two Spydercos till now, and the first one also was an Endura (VG10, blue handle). Really loved this knife, it was my most carried by far at the time.
Lost it on a mountain hike, must have fallen out of my pocket somehow. When I realized it was gone I turned around and went searching for it, with a headlamp, for it was dark already. I made almost 6000 feet (1800 Meter) of vertical distance on this mountain, just while looking for the knife, but it was gone for good...
Since then I make sure that the pocket clips on my Spydies are rather tight, sometimes to achieve that I bend them down a bit more.
Top three going by pocket-time: Endura 4 in VG 10/Micarta-scales; Stretch 1 in VG 10; Endura 4 in HAP 40