I have always been very, very suspicious about the purported trajectory of the round that exited lower on her back than the entrance wound was on her front, esp. since that was the round that went through her lung. To follow that path, the round would have had to travel somewhat vertically through her body and be fired by someone much taller than she was. Yes, MB was much taller but didn’t she claim to be on the steps when he fired at her? And why would he have aimed at such a steep downward angle to cause the vertical trajectory?
It always seemed to me that the only explanation for that trajectory was that they were on the ground grappling for the gun, and I can even see a scenario where they were both lying on their stomachs facing each other when the gun discharged.
Edited to add that I forgot how RG described taking MB to the ground but if MB was already down on the ground on his stomach grappling with LK, that would have made it much, much easier for RG to get on top of his back.