I do something similar. The vast majority of my knives are tip up, which I prefer, and which I normally carry very close to the back edge of the front pocket, making it impossible for them to open accidentally. So, on one of the few occasions when I took one of these knives and put it up against the front edge of the back pocket, it did not go well.
The specific knife was a Masters of Defense Michael Janich liner lock knife that I carried frequently around 1999-2000. The liner lock did little to hold the blade closed, and without the blade against the edge of the pocket, the knife worked its way open when I shoved something else in the back pocket.
I currently carry either Waved Spyderco Delicas and Enduras, or Cold Steel Storm Clouds and Recon 1, all of which are much better at staying closed when they need to stay closed.
I believe some have been made at various times but I don't know that any have caught on. I have found that better knife designs carried in a safer way is a better solution.
The problem with any liner lock is that the corner of the lock bar closest to the cutting edge of the blade will experience significant wear and tear, eventually failing to hold the knife open. Frame locks are supposed to reduce the problem, but will eventually experience the same issue, in addition to interference from the lock bar to opening the knife. I have come to prefer rocker bar locks and ball bearing locks, which protect my fingers when open and have a reasonably strong bias towards closure when closed.
Likes pretty much everything in every caliber.
I carry slip-joint knives in the pocket so no clip to catch. My belt-mounted support side appendix Bowie-pattern CRKT Minimalist has never been an issue. Nor has my ASP Key Defender with QD keyring tucked into my waistband support-side appendix.
If you guys would just switch to shooting left handed and carrying the knife on the right side...
I was thinking that losing the knife on drawing never happened to me and then I realized...
The first indication a bad guy should have that I'm dangerous is when his
disembodied soul is looking down at his own corpse wondering what happened.
"Gunfighting is a thinking man's game. So we might want to bring thinking back into it."-MDFA
Beware of my temper, and the dog that I've found...