[DannyTN]

Possibilities:

• Crew was infected
• Tests were bad on either end.
• Tests on arrival were contaminated.
• Previous flight was infected and virus particles still lingering in the air.
• One or more passengers was infected but not yet shedding enough virus to test positive.
• Exposed at airport waiting for flight
• HK government now CCP intentionally detaining passengers for unknown reason.

  It takes 5 hours to fly from India to Hong Kong. I doubt that's long enough for the virus to incubate.

[DugwayDuke]

DannyTN wrote: “Possibilities:...”

You might also add: Passengers submitted forged/false documentation.