Not sure what or where you guys/girls (Death Pencil and beer bong) fly but I can say from experience that its not only not making the required radio calls but in some cases just not understanding instructions that is plaguing Parafields skies. Not to mention the lack of understanding of other aircraft performance. These incidents are not only limited to outside tower hours.
I would suggest in a number of cases it has been other pilots good lookouts that have averted accidents in the area. It would seem that in strims case the other pilot wasn't looking out, making calls or understanding strims.
As for speculations on a rumour network.... pretty sure your reading them