Sounds like you're describing surgical failure in Rimworld "alright just removing the infect finger.. And...ah shit I accidentally stabbed him in the face 25 times and killed him"

The problem as I understand it is that people try to dig/slide the pit out of the avocado with the knife and their hand slips. The safer way is what you described - choose a knife with a bit of weight, draw it back a few cms and give it a nice whack, then with the knife firmly embedded, twist to release the pit.

Just consider the relative hardness of your flesh versus the pit. And the fact that while you intend to hit the pit straight on, imbedding the knife, if it slips sideways, by the time it hits your skin it's going to be moving in a slicing motion, which obviously makes penetration of skin and tendons easier. What's so difficult about laying it on the cutting board? You're still allowed to hold the end of it for stability, just don't put your palm behind it.

Either way, you're not supposed to smash the pit, just tap it with a sharp knife so that it gets deep enough into it so you can twist it out. It sounds like people are swinging their knives like swords to try to get their knives like halfway deep into the pit lol

It doesn't harm it at all. The knife sinking into the pit absorbs the shock, and besides you're about to eat it. Most injuries aren't caused by terrible aim, they're because the pit is slippery and curved, so just a little wrong angle can send the blade sliding off and into the hand. Especially when people whack too hard, and/or started the tequila or cannabis before the guac. That's why you make putting it down a habit, so your muscle memory will override your stupidity.

If you're not going to eat the whole avocado, put it in the fridge with the pit still in it (and the open part covered) to keep it green.

You can get a new table