I guess for the cannonball myth they waited longer for things to settle down a bit given the mishap to make it a bit more in the "forgotten past."
Kari said as much in the episode. After the misfire and the accident, they suspended testing on the myth, then spent months engaged in community outreach and reassessing their safety procedures, and only when they were confident that they could proceed safely, they resumed testing in a more remote location and using a more reliable cannon.
I do wonder how the "SimDaver" would have survived the initial myth tests rather than the more rigid dummy.
It's SynDaver, short for "synthetic cadaver." A representative of SynDaver Labs has been posting here under their company name for a few weeks.
I also wonder why they didn't test the dummy in different falling positions. I can see all of the pelvis and spine damage coming from the fact that it was landing directly on those parts as opposed to trying to "land flat" to disperse the damage more, a "cannonball" type landing or something else. Landing directly on your ass, sure, makes sense you're going to mess up your pelvis and thus lumbar spine.
I think the idea was to land relatively flat to distribute the weight, but from the way the stunt diver did it, I don't think that would be the right way to go. The stuntman had Jamie go in feet-first, minimizing the contact with the water surface, and then flattening out once he was under to maximize his deceleration. That suggests that landing flat on one's back in the water would create too much resistance and impart too much deceleration to the body all at once.
Yeah I was really surprised they showed that myth, especially with how definite Adam sounded at the time of the incident that they never would, and how generally uncomfortable the hosts all acted anytime the subject was brought up.
Makes me think the network might have pressured them to show it for ratings or something. Or maybe they just needed a second myth for the episode and that was the only one available.
I'm willing to take what the hosts said at face value -- that once they'd rebuilt their relationship with the community and tempers had cooled, it was deemed all right to proceed.
Wikipedia says:
The Dublin Film Commission declared December 6 "Victory in the battle for Dublin", poking at the rogue cannonball incident, and plans to host a Film Festival every December 6 to honor Dublin's fallen cannonball.
I assume that sentence is supposed to say "poking fun at" the incident. Apparently the community is being good-humored about it in retrospect, and presumably gave the show the okay to proceed with the experiment.
I think showing the experiment and making a public apology was a better, more responsible approach than trying to pretend it had never happened.
In any case, it was kind of impressive that Tory's little homemade cannon was capable of such a powerful blast. It looked like the cannonball shot through the concrete wall like it wasn't even there!
The official report said the cannonball missed the water barrels, went through the cinderblock wall, and skipped off the hillside that was supposed to stop it. I'm a bit surprised the bed liner didn't stop it. From what I've seen, that's pretty amazing stuff.