Murder of crows silent assassin rating

A Silent Assassin rating is earned by completing the following objectives:

• No bodies found, unless the death is made to look accidental.
• No witnesses.
• Cover kept intact throughout the entire level.
• Any captured footage collected (surveillance tapes).

Furthermore, on Expert and Professional difficulty:

• Left level with suit.
• Left level with all custom weapons (weapons brought into the level).
• Left level with the diamond case

Here is a link to the IGN guide, where the writer achieved Silent Assassin in 17 minutes on professional. The methods for killing the targets appear identical to yours.

I am going to assume it is the diamond case you are missing. The guide details picking it up at the start, and stashing it for collection at the end.

From your starting stand still. You'll notice a man dressed in a red bird suit will enter the restaurant and walk over to the bar. He will talk with a civilian before leaving. He has the diamond case. Now the case is important for two reasons. One, you need to retrieve that case to get an SA rating as mentioned above and two, if that case reaches Mark Purayah then Kulinsky will make his move on the politician. In other words if that case does NOT reach Purayah then you will have no time limit what so ever on this mission.

Now when the red bird leaves the restaurant he will either head left or right. If he heads right just restart the mission as it's much easier if he heads left. Follow him making sure to stay on the opposite side of the road from him. After a little while he will head down a narrow alleyway and into an open square. Quickly sedate him as soon as he enters the square. Drag his body through the door on your right and hide his body in here. Take his suit and head back out to the square. Pick up the case and place it in the room where you dumped the red birds' body. You'll pick it up later on.

When it is time to escape;

With Kulinsky taken care of make your way back to the central square with four paths leading into it (where you sedated the red bird). Once you arrive there head into the small room where your suit is and change back into it. Then pick up the diamond case and head out the room. Take the southern path out of the square, walk over to the small metal barriers and escape.