The Hughes/MD 500 (369) helicopter has a jet turbine engine that uses Jet-A fuel. Filling up with auto gas from the tanker truck would not work well. The engine would be damaged and would not get very far.
Walker was flying with a microphone in his left hand. The left hand is always used for the collective, so in this case a co-pilot must have been used. Normally helicopter pilots would be using a headset with attached microphone.
The call sign heard for Walker's MD500 was "329 Foxtrot" which would be incorrect since the registration number is N9103F. It should be "9103 Foxtrot"