I'm sure the cuts were specified by the air board. When these programs first started, the air board guys administering them just required a hole to be cut or punched in the block. (Frankly, most of these guys are good, regular people with a job to do. Some of them are as frustrated as us to see these good tractors cut up and new ones paid with their tax dollars, but they have a job to do.) Pretty quickly, the powers that be figured out that repairing a hole in the block is pretty easily, especially when the guy cutting or punching it was pretty careful about where he put it.
Once they got wise to that, they started specifying more and more destruction in their "Certified Destruction" instructions. If the owner wants to follow the destruction path, they do a pretty good job of making sure that machine is economically unrepairable and most of the time, they want to ensure that the significant parts are not useable for repair of another older machine. These surprised me because from what I've seen in our area, they pretty much require the largest dimension of the largest intact piece of the machine to be less than four feet. That means the tracks have to get cut, frames, everything. About all you can save and resell is the knobs and some small stuff.
The destruction can't be done by the owner, it has to be done by one of a few approved vendors, mostly scrapyards. When the machine is presented for acceptance into the program, the air board inspector visits the owners yard and verifies that it starts and moves a bit forward and back under its own power. Prior to that, the owner can have stripped off anything he wants. As long as the machine is fundamentally complete (has all the tires, even if they're flat and bald, etc.), starts briefly and will move a few inches forward and back, it can be accepted.
Once accepted, the owner moves it to the certified destruction scrapyard. There, they follow the destruction guidelines, photograph the start, progress and completion of the process, including all the serial number tags several times during the process. The owner then files the photos and certificate with the air board, places the purchase order with the dealer for the replacement machines and the air board funds the reimbursement to the dealer.
I suspect that these were much more gently handled because I'll bet the air board had to relax their destruction standards because of the price of scrap. They probably couldn't get certified destruction vendors to participate because they'd lose money processing the destruction because the remaining value of the scrap wouldn't cover the cost of processing.
Someone could get some very nice undercarriage, and probably some other really nice parts, looking at these machines. Depending what else was done, they almost look like they could be resurrected.
By the way, destruction isn't the only way these machines could be handled. Permanent removal and sale outside the air basin is another option. This participant could have sold these tractors to someone in Nevada, Arizona, Oregon or anywhere outside the central Valley and South Coast area and gotten the same reimbursement. Sales outside the basin don't often happen though, especially for machines of this size because of the economics of selling and transporting the machine. They just don't have enough utility left to justify the transport costs.
I did try with several machines I thought were interesting to convince the air board to allow retirement in place, with the machine relegated to hobby and history preservation status. No dice, if it could run and generate pollution and remained in the air basin, it wouldn't qualify.
Pete.