If there is a conflict between a model and an aircraft it is the model pilots fault.
And yet - who pays the higher price if the worst actually happens? I don't think fault or blame is a good way of looking at things. If there is a conflict between two real aeroplanes, the plane that has the other plane on its starboard side must give way. But if you're the other pilot (who has the other plane on its port wing) [I've been there] and you don't see them taking any action, do you just wait for the inevitable to happen? Risk killing yourself and people in the other plane, as well as people on the ground because you had right of way? Or do you take evasive action?
Just talk to one another, even go for a beer to chat about setting up procedures. Put a safe plan in place, make all model club members aware of these, and all instructors/members of real planes aware of those too. Save the risk of thousands in damages and potential loss of life, by just having common courtesy & talk to one another!
rant over...