Well this is my first post and i'll keep it brief. I have been lurking around for quite some time but never had anything to post. Over the weekend while riding the local bike trails, I came across a root in the trail that seemed to be hazard. only about 3/4" in diameter, i decided to cut it with my crkt m-21. I failed to use the secondary locking mechanism, since i have never had a knife with one and also never had a lock failure. I whacked the root good, and as it went through, the lock failed and the blade closed on my hand. As momentum carried it through the stroke, the blade snapped back open and locked. Off to the hospital for 6 stitches and a partially severed extensor tendon. Worst part is I am a LEO and the injury was my right index finger. Looks like i'll be off for a little while. Anyone else experience a similar failure with this particular knife. This knife was a recent purchase, having carried a cqc-6 and several cqc-7's for years. I still like the knife, but my confidence is somewhat shaken now.