Did Drake know that Sam was still alive? If so, he would continue trying to kill him. Perhaps the fiery destruction of the panzer had made Drake’s tool Tessien believe that both Sam and Begay had perished in the wreck. Jacqueline had implied as much. Lofwyr’s statement that Sam was an "unanticipated player" also confirmed the notion. If Drake believed that Sam was dead, that slim advantage might allow Sam to get to Drake first.