Digger, I've never shot a hog with a 22 LR from more than 30 yards away or from anything but a steady rest with an accurate rifle. Not enough energy in the 22 LR for longer shots. Not enough stability to shoot them off hand, they just move too much. It is the front of the forehead or NO SHOT, period. These are my self imposed restrictions with the 22 LR and I stick to them for good reasons. I get PLENTY of opportunity and it does not bother me to pass up any shot. That 30-30 shot you describe was a bad hit. It grazed the hog. It didn't bounce off.
If some kid reads only that portion of this thread that suggest to him it is OK to hunt hogs with a 22 rimfire, and nothing else (the probability of that is very small), then that kids is in for a rude awakening on some level of hunting hogs. That kid is going to learn the hard way, just like you and I did.
If we look back on our lives (maybe just our hunting lives), we can see instances that make us wonder, "Why am I still alive after that?" Not every life lesson is learned prior to the need for that information. Sometimes getting hurt, losing game, falling out of a tree, not using enough gun, getting stuck by a wounded hog, etc., is learned the hard way. Life is HARD. There is no guarantee for safety, security, or freedom from hurt and pain. Every conceivable scenario will still be far short of the realm of possibilities, so we're better off letting the lessons come as they may, sharing with one another to increase the collective intelligence, and letting those on the edge of that intelligence, sometimes you and me, take the brunt of it. It is hoped the lesson is not learned at too high a cost.