When I was in DXB last week I spoke to one of the Skywards staff who are located within the J lounge in T3. I asked about the whole "overdraft" thing when it came to miles and the lady advised me that Skywards will, in certain circumstances, allow a members account to overdraw by 2000-3000 points.

In your case, you can clearly demonstrate a booked revenue itinerary. I would make the request and see what they say - after all, they can only say no. And I would ask more than once if the first response was no.