To be more specific, they (one of my employees) told me they were landing at lunchtime (the phrase “in transit” was mine and slightly misplaced) and would therefore not be coming into work.

Said employee was sending WhatsApp messages between 11:30am and 2pm, and the only flight data for their route shows a flight that arrived before 11:30am having landed at 9:15am.

Whatever the reason for the inconsistency, it seems that onboard WiFi is not an explanation....