Think about it. If you have kids or pets or flowers, seems like it would be prudent trigger the event in a more safe, and known environment than to leave to chance (of injury to property or 3rd party). Seems like talking to the neighbor happened over a decade ago to me.

Sure, depending on the chances of it happening. The problem is that we don't know what the chances are, and as a species we're fairly bad at assessing stuff like that in general. If it's a million-to-one chance, there are probably plenty of other more worthy perils to be concerned with first. If it's a hundred-to-one chance, it may be an imminent threat. Which is it? How do you trust that the person telling you the odds isn't vastly over or under estimating the chances?

The answer falls into an area that's somewhat unknowable with current information, which is why I can't fault either behavior.

I disagree. We know that the probability of it happening again is very high, seeing as it has already happened multiple times, and no serious action has been taken to improve the situation. If we were speculating about a theoretical risk, I would agree with you.

I think the issue is less the chance of the lawnmower going wild by itself (because screw that, I don't care how small the chance is, it's not acceptable), and more the chance of the lawnmower exploding, taking out your eye when you trigger it's failure it yourself.

As in, "the chance of getting hacked" < "the chance of the vigilante creating dangerous situations".