No LNer believes that is an accurate timeline. Oswald's movements in minutes leading up to the assassination are uncertain. The evidence, however, places him in the SN at 12:30 beyond any doubt. You have also falsely suggested that JFK's car was "behind the foliage of a tree" when the shots were fired. As apparent from the WC recreation of the event, his car was in a clear line of sight on Elm from Oswald's window when he was struck. An easy shot for Oswald who was trained in the USMC.
Oswald's movements in minutes leading up to the assassination are uncertain.Of course they are. That's exactly why Jesse Curry said that nobody has ever been able to place Oswald on the 6th floor with a rifle in his hand.
The shooter (if there was one in the so-called sniper's nest) needed to get into the nest on time for the arrival of the motorcade, which was scheduled at around 12:15. There is no evidence that places Oswald on the 6th floor around that time. However, Bonnie Ray Williams was there and he did not see or hear anybody, when even the slightest footstep would have made the wooden floor crack. On the other hand, Carolyn Arnold saw Oswald (iirc) on the 2nd floor somewhere between 12:15 and 12:25. And Oswald himself saw two co-workers, we now know to be Jarman and Norman, as they were walking towards the elevator on the 1st floor at around 12:25.
The evidence, however, places him in the SN at 12:30 beyond any doubt. You really need to stop telling the same lie over and over again. Even more so now that so-called "evidence" has been completely debunked, whether you like it or not.
The fact is that you still haven't been able to explain how Oswald could have gotten on to the 6th floor without being seen or heard by anybody, how he could leave that floor, after the shots, without the guys on the 5th hearing as much as a crack of the wooden floor and how he managed to get down to the 2nd floor lunchroom in less than 75 seconds after the last shot, without being heard on the noisy stairs and/or being seen by Dorothy Garner, who was standing next to the stairs on the 4th floor.