Well, this sling attached is just one more item to add to list of things omitted at the CBS shooting trial, that the shooter had to contend with.
Other things include
1. Not having box on window ledge or using box as a rifle rest.
2. Red target on dark blue/black background on a clearly visible track
3. Shooter able to work bolt right up till time to shoot. Actual shooter did NOT do that for at least 5 minutes prior to shooting as Harold Norman beneath the shooter on 5th floor heard no sounds before the shooting began. Bronson film started approx 5 minutes before JFK motorcade arrives, shows box in window, which only the shooter would have placed.
4. No tree obstacle
5. No other boxes stacked to replicate the cramped space of this SN
6. No vertical pipes on the left of the box in the way.
7. Shooter allowed take position in window before target begins down track. Actual shooter had to remain out of sight via Hughes film, and had to move into position, get set up, and then try to acquire moving target, a black solid in front of a dark blue rear portion of trunk of limo, which had reflective glare from sun.
8. shooters used the scope.The scope could not have been in alignment in the elevation due to requirement for shim underneath mount to make that possible.
9. no window frame, and no window at 15.5 inches open.
10. no sling to potentially get hung up on something, like a box corner, or otherwise interfere with shooter holding the stock while firing rifle.