Would be pretty hard for a court to prove you could not have "landed clear" wouldn't it (in the same manner as only a pilot can tell the in flight visibility)?
Why would it be that difficult? Is the glide ratio of a specific plane really unknown and impossible to determine?
I think it would be pretty trivial for the prosecution to show, based on your radar track, that an engine failure would have resulted in you not being able to land clear for a significant portion of the flight, and this is really all that this is about.