Maybe BamBam was not too keen on the idea of leading out, given the tighter terrain, greater number of notes/instructions and the general intensity of the navigation/roadbook side of things? By starting on pos 4. at least he had a few others to follow? looks like the others just did a better job on nailing the ICO/route instructions.
Coma on the other hand had more "hares" out the front and his own roadbook skill/navigation is usually pretty much impeccable.
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