I was watching GF II on tv today and as I was doing so, Mike was talking to Anthony after the assault and Anthony asked Mike if he got his present - Anthony's drawing. This would mean Anthony was possibly the last and only one to have entered the room. He may have opened the drapes after being asked to do do by Pentangali. Although it was not shown as was so many other plot holes, Pentangeli may have asked Anthony to open the drapes for what ever reason - Frankie may have said something to the effect - " Anthony, your dad wanted me to ask you to open the drapes in the bedroom, so that he could look out on this beautiful night. He would have asked you himself, but he got busy with business. Don't say anything to him, he gets embarassed when he has somebody deliver messages for him. "