FRRO — airlines (air india)

I am dr geet oberoi from delhi and i write to share my husband's horrifying experience with air india at singapore airport today morning (8th sept 2018). My husband randy k bradbury who is a us national with a valid 10 year tourist visa (Multiple entry) was not allowed to board the flight from singapore this morning (8th sept 2018; ai 381). The reason stated was that the valid visa was in his old passport which had expired. Both the expired and the current passports were together with all other paperwork in place. What air india did is most irregular.in all online forums and at at the frro, new delhi, it is stated that a person may travel with a valid indian visa on an expired passport.
Now my husband is there on the weekend with no clarity on the state of affairs. He is stuck there for at least 3 days as he has been asked to apply for an e-visa.
I demand clarity on this issue. If in case air india has changed its policies then why are all online portal saying otherwise? Why did frro give incorrect information? Can an airline over rule the laws / policies of frro?
Who is responsible for the forced extended stay in singapore and not to mention the huge added expenditure?
I would request this issue to be resolved asap with a return flight with ticket and the compensation of the extra days there covering all expenses.

The following are a few of many links available online which state that valid indian visa in an expired passport works.
Also attached are his ticket and valid 10 year tourist visa with multiple entries.

https://www.immihelp.com/nri/indiavisa/transfer-of-india-visa-new-passport.html

https://www.youtube.com/watch?v=Ey7nARBq4GQ

https://travel.stackexchange.com/questions/87023/can-you-travel-to-india-with-a-...⇄passport

Thank you

Contact of traveller - randy k bradbury /[protected]@gmail.com / [protected]
Wife of traveller - dr geet oberoi / [protected] / [protected]@orkidsped.com