I have some problems with this article
First of all, whole the He3 mining thing seems to be written by someone who failed economics. What difference does ownership of the ground make when the entire lunar surface is effectively a He3 mine? It isn't like mining materials on Earth where there are limited areas/seams where the good stuff is found, surrounded by a lot of crap.
The incentive to develop technology to exploit it would come from patents that protect you from others using the same method as you, ownership of the ground you're mining would be pointless and unnecessary, because if someone else develops a competing process and they have no reason to want to mine the same ground as you. Though I suspect given the time required to ramp up commercial operations, rather than patenting He3 mining technologies they'd be kept as trade secrets. It isn't as though people could sneak up on your operation from the next crater over and figure out how your machines work.
Maybe ownership of "land" starts to matter if there's a lunar settlement, since ground nearer the settlement would be more convenient to mine that ground hundreds of kilometers away. By the time there is a full time settlement on the moon, housing people engaged in purely commercial, as opposed to research, activities, the moon will need to have a functioning government of some sort that will regulate this sort of thing.
Second, I'm curious exactly what we'd be hoping to mine on asteroids. Mining gold would be clearly stupid, because if you find a way to get many tons of gold from asteroids, the price of gold would fall through the floor, just as it has in the past when major additions of supply came online - except in this case, the potential available supply would be almost limitless, so the price would drop and never recover. Gold's problem is that has little use, mostly we dig it up so we can bury it in the ground again in a safe. Maybe platinum or palladium would be useful to mine, since they have real uses, but if the supply increases greatly the uses would need to as well or they'd suffer the same fate.
I hadn't ever really thought about it before, but I guess the author has a good point that there would be an incentive for miners to sabotage each other, as the less the guy on the next asteroid over brings home, the more what I bring home is worth. That would tend to increase the risk and therefore cost of mining and this needs to be taken into account by anyone hoping to make a commercial profit from mining.
I am skeptical of the whole idea of mining asteroids to bring stuff home, at least not stuff we already can get here like gold or palladium. I suspect most/all asteroid mining will be for things that are built in space, or on the moon, rather than returned to Earth where we already have plenty of materials to build stuff. The cost of lifting materials to orbit, or to the moon or Mars makes those materials worth 100x more in orbit than they are once you drop them down to Earth, especially if others are doing the same. You may not need a whole lot of gold to build a lunar settlement, but even the cheapest metals like zinc would almost certainly be far more valuable delivered to the lunar surface than gold or platinum would be delivered to Earth's surface.