Certainly sounds like it from the symptoms described.
I had the same happen to me on my '05 RT which left me stranded in Ireland. It was the wife's 1st proper trip on the back and her introduction to the 'joys' of motorcycling - not a great start as we lost 3 days of the holiday getting it sorted. And on the days the bike did work we had constant heavy rain & high winds. Still I guess that was my fault for going in July.
I thought the Fuel Pump issue had been resolved now but there's a 'sticky' on the GS forum suggesting otherwise.