On 25 March our Chief Minister said:
"There will be no commercial flights or light aircraft permitted to land at Ronaldsway Airport beyond the last scheduled flight tomorrow. The only exceptions will be for emergency medical transportation and the mail flight."
I guess the a number of "essential" personal permitted to travel decided they didn't fancy the boat and train so the London flight was allowed to carry on. Loganair continue to operate the Liverpool patient transfer service, too.