That parents are crazy(sorry, forgive me, I said that).........did your friend take his kid to see doctor? If yes, ask the doctor write a letter for your friend, and ask your friend take the letter to airline, it might help to change the date............we live in UK, and we were in HK at 2004, then my twins got chickenpox, but we had back to UK soon, so I asked the doctor and wrote me a letter, I took the letter to airline and changed our date 2 weeks later.............hope it helps your friend............