Dwarves will be dwarves - I'd say stupidity is almost as ubiquitous as dwarves and their booze in the realm of people who know DF and don't play, and more ubiquitous in the player realm.
I've never had a dwarf die to building on the wrong side - I've always watch when things are being built - nor due to wrong channeling or mining... (had close calls though, good medical systems have saved dwarves gotten whomped by cavein dust before.)
I have had times where I've ordered a lever to be pulled, and it assigns the only dwarf in my magma forges at the time, over 117 steps away - the farthest dwarf from the lever. Said lever was for the drawbridge for my entrance - all soldiers were in the caverns at the time, fighting off hordes of undead.
wow - I'm rather derailing - fact is that I've only had 3 dwarves ever die on me in any of my forts. 2 were from failed moods, and the last one was from a FB syndrome.
The 2 failed moods were dumb on my part, easily preventable, since my fortress at that point was able to supply any material that a mood needed. I simply forgot to check the workshops due to a megaproject, and see that the craftsdwarf was screaming for tanned hides when 2 doors down there was a roomful of cows waiting to be slaughtered, and a tannery 3 doors down waiting for the skin.