Whats going to more interesting is how this case might be prosecuted in that will they look at the pilot qualification to conduct his private flight (in which case what duty of care does any 3rd party have to check such qualification?) Or will there also be a focus upon cost sharing and how any reasonable defence that it may have made that element legal.
After all aside from financial transactions providing a trail - which ultimately i suspect will be key. But absent of which you suggest to a potential pax that he might give Bloggs a call to make a trip and it goes wrong essentially because he flew at night and into IMC has little to do with paying 1% or 50% or his legality to fly an N registered aircraft. It might have been reasonable for the 3rd party agent to expect the pilot not to fly in IMC or Night given his ability to survive 2000+hours before....