Something I thought about. What if Kit Harrington isn't lying. Maybe he is NOT coming back for season 6. Because his scenes for season 6 had already been filmed. They had Melissandre at the Wall with Davos. They could be doing where they only are using him for 2 episodes next season and wanted to keep his death under wraps. So they filmed his season 5 scenes during season 5.
Something I never thought of. Dan and Dave might've thought ahead. They knew everyone would be scouring the season 5 shoots to see if Kit was filming. Notice HBO gave GAME OF THRONES a 2 season pickup with season 5 & 6 (it's only been 1 season at a time before). It could be Dan and Dave requested that because they had in mind how they would pull off the surprise of Kit's return.
Something I never thought of. Dan and Dave might've thought ahead. They knew everyone would be scouring the season 5 shoots to see if Kit was filming. Notice HBO gave GAME OF THRONES a 2 season pickup with season 5 & 6 (it's only been 1 season at a time before). It could be Dan and Dave requested that because they had in mind how they would pull off the surprise of Kit's return.