No, I'm suggesting someone moved them up there as soon as the (real) SN-----where the shells were-----was discovered. Because that was when they realized they'd gone to the wrong window initially (fifth rather than sixth floor)
??
The first officers to discover the SN reported seeing the lunch remains on/in SN.
Why would they report seeing the lunch remains?
Why did the people on the 5th floor, who you think discovered the lunch remains, feel the need to move the lunch remains up to the 6th? To avoid embarrassment? Lower ranking officers decided to rearrange the crime scene evidence of the most important crime in America's history to avoid embarrassment?
Let's imagine the lunch remains were found on the 5th as early as 12:40 PM. Who was reporting the lunch remains proved the assassin was on the 5th floor before the SN was discovered?