Ramjet
From the Pilot himself, if he filled the tiptanks he would, when instructed to leave RVSM airspace had to descend to FL270. Without the tiptanks filled he could have climbed to FL390 like he did. FL270 with full tip tanks would have caused him to arrive with less fuel than what he did.
This would have been a much worse situation than what he found himself in, on that particular night.
From what I can see, this whole thing was a complete schommozle, from the company flight planning equipment (non existent) to the ops manual, to the training, to CRM, to pax briefings, to the aircraft that was being operated.
Disgusting.