I was thinking the same thing about liner lock knives. For about 18 years I carried a Case Sodbuster around the yard and garden. It has a brass liner lock. Except when using it I always kept it closed. Recently I retired it in favor of a BM Panther. While examing the old Sodbuster a day or two ago I realized how little pressure would be required to force the blade closed. I guess this knife would fail the "whack" test as I think I've heard it called. To be sure, this Case liner lock is not the equal of current linerlocks available from quality knifemakers, but when I bought this knife back in '80 or '81, I remember feeling that the lock was positive. Hmmm...maybe I'll store the panther in the open position.
ptn