Did you mean first order or second order kind of like the way physics people mean it (direct linear relationship with strong effect on the unknown variable). Or the way that MBAs mean it (they have their own definition).
Or did you mean structural engineering, same as physics: https://www.quora.com/In-structural-engineering-what-are-fir...
I think what you probably mean is a colloquial interpretation, where first order means something is directly causal in an obvious to see way, where second order is more of an indirect effect that occurs through complex dynamics.
Either way, I don't think those terms are well defined, and they're kind of complex enough that using them to argue for morality, and calling people out for not knowing your definitions, makes you look caddish.
I doubt that they could mean causally indirect. I think it must mean something like: not used in accordance to their the engineer's intent, especially when that intent covers a a general affordance (e.g. affords communication over long distances), but is being judged for a more specific affordance (affords communication over long distances to order a terror attack). I dunno. I'd have to be a philosopher to work it out.
The problem of where to draw those lines is so difficult that legal systems resort to constructing tests based on whether a "reasonable person" could have foreseen the specific consequence of an act.