> 3. Had the higher-priority request arrived even one millisecond earlier or later, the update would have completed normally.

Well, that's comforting to know.

BBC: "Flight chaos caused by software defect in space of a millisecond, report says"

Sky: "'Millisecond' software error caused air traffic outage that grounded thousands of flights"

The Guardian: "Flight chaos for hundreds of thousands was caused in ‘millisecond’ by software error"

Sounds like pure bad luck.