For me it is strange. It is like car accident, when car hits a man. If driver was drunk and didn't help victim i would understand if someone would kill him in revange. But when it was just accident becouse of some negligence - for example driver was sleepy or was talking by mobile phone it would be hard to justice. How can we kill someone becouse of using phone during driving.? Yes he killed but rather by accident than becouse bad will.
So for me I can understand this guy but i would not act like he did. Maybe I would just "talk" with this air controler to arouse his conscience. Prisons exist only becouse some people don't have uneasy conscience imo.