Personally, I'd also put that down as an example of how a fixation on guns leads to failure. A truck attack or bomb might have been far more devastating.
Especially since it sounds like his substitute gunpowder worked.
Seconded. Against these idiots I think if anything guns are a safety measure. Using a large vehicle (rent a moving truck, load it with something like concrete blocks from your local hardware) and ram is actually more deadly than most mass shootings. Guns only have an advantage if you seek specific targets rather than simply a death toll.