In Lois McMaster Bujold’s “The Borders of Infinity”, there is the following passage:
"Was—was he injured when Fallow Core was overrun?" asked Miles. "Head injury?" Oliver shook his head. "Fallow Core wasn't stormed, boy." "But it fell on October 6th, it was reported, and—" "It fell on October 5th. Fallow Core was betrayed." Oliver turned and walked away before his stiffened face could betray any emotion. Miles knelt in the mud and let his breath trickle out slowly.
What was the significance of this revelation?