Well. IMO the rule of thumb is that ariplanes and helicopters SHOULD NOT share an air space. They should be far apart.. with a dead zone.
Second... if there is a crowded field.. like you would see in a lot of Funfly events, you should always have a spotter, in this case, the plane guy had spotters, dont know about the heli guy. but spotters help a lot in a crowded field. THats why they dont even let you fly in the main flying air space in a fun fly event if you dont have someone to spot you .
Third.. The low pass was called. The guy should have heard it and steared clear. htere is something I have seen .. because plane esp the scale guys fly pattern, most call their low approaches, touch and gos , landings and take offs. or even emergencies like dead sticks.
Heli guys .. more I have seen, are used to their own air space... and being a heli guy myself like to "hog" the airspace
. we dont like to remain in a small area. One time I would be tic tocking in a 10 foot by 10 foot area.. and the other I would be doing a hurrican size of a football field.
Right of way .. is always given to the planes.. cause they cant stop at the drop of a coin and hover. they are moving wheather the pilot wants or not
helis can stop and stay..