Do away with camp rules...

[Tethler]

If the guy claiming Crush/D'vinn dies or zones out he forfeits the camp, as per server rules. If your group can get back to spawn before him after the train, it's now your camp. Also, if he doesn't engage a contested spawn in a "reasonable time" he loses the camp. "Reasonable time" can vary by guide/GM, but within a couple of mins is safe for your group to engage if he has not done so.