I think that what Gregorio said is correct. Same thing happened to one of my Speedplay cleats a few months ago (replaced under warranty).

Ach! Quit cher whinin'! I was at a race today and some poor guy pulled his cleat right off his shoe!!

_________________
it's actually possible to come to the conclusion even before realising it makes no sense at all
-
tymon_tm

your cleats look fine, they are the right ones, dont look broken, but the wear marks on your steel protector seem a little odd. how old are your pedals? could be worn bowties as mentioned, could be worn edges on the pedal bodies allowing angular movement. i would check that the cleats sit square. by that i mean that if you look at the front of your shoes head-on, the front of the cleat should be on the same plane as the rear of the cleat. if there's a twist, correct it with the "extra shim" provided. good luck.

Not missing, that is correct.

Also, ensure the c-clip has the * side up, they are tapered slightly on one side for entrance into the pedal, if you have them upside down, I would assume this would allow for them to unclip easily, even without twisting.

I've forgotten to locktite the screws on my cleats 3 times after adjusting them. Each time has resulted in lost screws. Really loose is relative, but you can't crank down on them much, or the retention ring will bind in the cleat - its entirely possible that the ring is being pinched by the plastic, and not functioning properly.

I just checked mine for comparison, and I don't think it is broken, just hidden due to the rotation angle.

The original picture isn't clear-enough (lighting/shadow) to be conclusive, but the C-clip may be upside down ? The bevel should be visible from the outside to ease entry.

I have been using Speedplays for a lot of years and never pulled out even once. But I suppose some people flail their ankles more than others.