Well then you likely don't have much to worry about regarding legal/moral responsibility. Still important considerations nonetheless.
In your case then, I would suggest:
Returning that knife and purchasing one with a solid locking mechanism at the very least. If you absolutely refuse to return this knife and intend to use it for other purposes, then don't ever open it in self defense and instead just use it as either a small weight to improve the mass of your punches or as an impact tool (butt/pommel strike).
If you choose to return in and get another knife purely for self defense/killing/maiming reasons, then some features to look for include:
-again, quality locking mechanism
-solid bracing features/mechanism (blood is more slippery than oil and there may be a lot of it should you ever truly need to use it in a life or death situation)
-some people prefer black coating for added stealth
-some people like "spring assist" or "gravity assist" opening mechanisms for faster access
-some people prefer a partially serrated blade to better cut through tough clothing (like denim or leather)
-you want a blade that can both stab and slash effectively. Some blade designs are only really slashing blades, and some are only really stabbing blades. Pick one that can do both; you don't want to get caught needing the function that you don't have.
This is "The Talon," designed by one of the best (in my opinion THE best) knife combat experts alive today, Richard Ryan. The original line is no longer in production (though, last time I talked to Rich he said he was looking into resuming production again soon), so I am just posting it to illustrate some of the above points to look for.
1) notice that the way the blade is positioned on the knife it would be nearly impossible for the hand to slide down it should you hit a solid target (this is further assisted by the "teeth" on the thumb brace on top of the blade, and the brace on the back side of the blade itself).
2) notice that the blade is not in a straight line with the handle. This allows the holder to grip the handle in any way and have the blade find the target first without the need to articulate the wrist. This makes for more solid gripping, even when slashing.
Here is another knife which seems to have taken some similar concepts. Not quite as ergonomic, nor as good for stabbing, but still has some good features.
And honestly, any decent "tactical folder" with a solid locking mechanism, solid bracing mechanisms, and an all purpose blade like the one linked below, are going to be light years ahead of what you currently have.