A friend of mine was on a jury that found a man guilty of manslaugter in a case where the victim died of injuries that normally would have been relatively minor. The victime however had a severe bleeding disorder, unknown to the defendant. The judge's instructions to the jury were very clear: An unexpectedly fragile victim is not a defense when you do something you know is wrong.
No, you are wrong. The situations are not comparable.
In America the standard is whether a consequence is foreseeable or not. That's what establishes liability. In the case you outline I agree with the result. When you attack someone to do harm you cannot later complain that the harm was greater than what you intended. It's foreseeable that that your damage might be greater than intended.
The proper analogy to the Concorde case is as follows. Imagine you were playing with fire works on the Fourth of July in your backyard. You toss a sparkler up in the air, the wind catches it, and blows it into the neighbors yard. It just so happens that their was a leak in the neighbors propane gas tank and the wind-driven sparkler set the gas tank alight, there is an explosion, the entire house is destroyed and the neighbor and his young kids killed.
I'd argue that blowing up your neighbors house and killing them all is not a foreseeable consequence of playing with a sparkler, absent any other modifying conditions. If you string together cause and effect long enough anyone can be put to blame for anything. The verdict against the mechanic in this case just doesn't pass the "smell test" for me.