Why would you assume Oswald fired the first shot in a sudden panic? He had ample time to study the layout. Why couldn't he have decided ahead of time, that he could probably get off a shot after the limo turned onto Elm and maybe 2 or 3 more after the limo cleared the tree. That first shot was the most difficult one but he had a better chance of scoring a hit than if he didn't take that shot.
He could have had the same mindset of hockey or soccer players. They know that the more shots on goal you take, the greater your chances of getting one past the goalie. Even if he missed that first shot, he would still have the chance to take the later shots. I wouldn't second guess his choices given that he succeeded in what he was trying to do.
1. Do you agree that the closer the 1st shot is to the limo as it goes down Elm st, the quicker the shooter had to adjust/ move the rifle to track the target JFK?
2. Do you agree that the iron sights on the MC rifle used by the TSBD shooter were probably zeroed for the range of 200 yards ( or meters ) ?
3. Do you agree that when the MC rifle was found that scope was out of alignment so bad that it required shims under the mount? The metal bracket was not bent so it looks as though the scope reticle could never have been adjusted properly with the elevation nob.
4. In your opinion , if the scope had been previously zeroed for a range of 100 yds , would it have lost that zero if the rifle was disassembled?
5. Do you agree that the 3 stacked boxes in the SN 6th floor TSBD were most likely used as a rifle rest by the TSBD shooter and thus indicate he had thought out in advance how he was going to fire his rifle in a calm controlled manner.?
6. Do you agree that the window was only open approx 15.5 inches per the WC photo using a surveyors measuring stick?
If you answered yes to the 6 questions above, then you must concede if the shooter stood up to take an early 1st shot, that he was taking a roll the dice 1st shot totally contrary to what appears to be his original plan to wait for the limo to go down Elm st far enough so that he had an easier shot using the box platform and when everyone is looking away from TSBD at the limo.