In my earlier days at the dealership, I got to carry many "blow outs" to the tire stores for adjustment, for the customer. Some of the tires were torn up from driving deflated/flat for an extended distance.
Once, on the parts truck, I picked up something which slung out. By the time I got to another dealership, the lh front tire was flat. This was in the earlier '80s. when tire sidewalls were more substantial and thicker. It did not fully deflate until I got to the intersection at the dealership. Freeway speed was 65mph or so. I got it changed and the spare installed.
When we put a new tire on the wheel, I noticed there was minimal inside damage to the tire, unlike the ones our customers had run flat. Of course, they said that as soon as they noticed something, they looked for a place to pull to the shoulder of the road.
The other day, I pulled out from a customer's shop and heard a clicking noise that was tire speed related. I felt nothing, so figured it was a rock or something in the tread. About 10 miles later, a loud roaring noise ensued. No control problems, but I could tell things were a little softer in response. By the time "the wobble" happened, I was driving slow and was headed to an off-freeway parking lot. The Michelin LTX was wasted. So I called in and requested a replacement tire/wheel, which was provided.
In the earlier times, we generally had UniRoyal tires on the vehicles we sold. The tire dealer was a good guy to work with. Even if the tire was "shredded", if he could not find a puncture hole in the tire, upon close inspection, he'd adjust it. If he found a hole he could stick a wire through, no adjustment as it was "road hazard" related. At a time when road hazard coverage had been deleted from tire warranties.
In more recent times, tire sidewalls are NOT nearly as thick as they were in the (for example) HR78x15 days. With the P-metrics, the started taking weight out of the tires and the sidewalls was ONE area in which that happened. Those older HR78x15 tires usually weighed between 28-30 pounds. A current P225/75R-15 is now closer to 25 pounds. Be that as it may.
The sidewall damage is related to low-pressure/zero pressure driving. The tread split might have been due to something else.
MasterCraft is what I'd term a "decent" brand of tire, that "works" for many customers. For a long time, they were sold by Farm Bureau offices in TX, but now have a dealer network in rural areas.
As for "passing inspection", those inspections are usually for tread depth only. I somewhat doubt that wheels gets "rolled" to look for bubbles/bumps in the tread surface, which might indicate a pending tread separation.
Many newer vehicles are engineered to hot really indicate a low tire as some of the older vehicles might have been. The rounded body shapes don't help determine if one end of the car is "low" when you're driving it, either! So until you might feel a softer response to steering or bumps, you might never know what's going on . . . even with a tire pressure monitor system. Some of the earlier systems used wheel speed differences to determine if a tire was low, using the ABS sensors. The tire might go down to 15psi before it would trip those, by observation. Current ones are RF controlled with actual pressure sensors in the wheel valve stems.
There's just not much "meat" in modern tires, even if they look good on the outside. Sorry you had this problem and GLAD you survived it in good shape!
CBODY67