How do I get back to india after just returning to USA?

My husband is in india now with his very sick and critical father. His returning ticket is for after 4 1/2 weeks which was the plan but instead of his father getting better from surgery it has put him in a critical state and is in a coma. The hospital bill is getting very expensive and I'm doing what I can to send what money we have but we now realise in order to keep up with the continuing hospital bill, my husband is going to have to come back to the US and go back to work so we can send money. More than likely his father will continue to be in a coma and a nonresponsive state when he leaves there. Its very hard for him to leave his father like that which is understandable. There is a law that says you can't travel back withiin a 3 month period once you've just returned from there. But what if my father in law pes away during that time? My husband has to be able to get there as soon as possible. Is there some form of emergency procedure he is able to do in case this happens? My husband is a US citizen. Thanks for your help.