Thanks to Steve Riley for putting us straighter on the booby trap story.
Seeing as the incident happened at the jump spot seems it was far more likely a pit dug by dirt jumpers than a trap of malicious intent. This was pointed out by Steve in his previous article so sorry we didn’t link it through.

Although this obviously has less worrying implications it still leaves a rider dead and should make folk take note to avoid digging holes where people are likely to ride into them, and be careful riding where people are likely to have dug holes.