That has always been an interesting aspect of Gov. John Connally's wounds: His two surgeons thought the SBT did not hold water.
Dr. Robert Shaw and Dr. Charles Gregory were not activists or leftists, and Shaw had military experience of working on hundreds of wartime gunshot victims. Shaw, without dispute, is an authority on the topic.
My take is Shaw and Gregory gave their earnest opinions and had no axes to grind.
Gregory found that a projectile had entered JBC's wrist on the dorsal side...almost an anatomical impossibility for a slug that first entered JBC's chest from the rear.
Shaw thought it most likely JBC had been hit by a separate shot, that shot had not been impeded before hitting JBC.
The small round hole in the rear of JBC's assassination day shirt strongly suggests a direct shot, and not a slug that hit JBC "sideways" after tumbling.
There are a lot of reasons to have reasonable doubts about SBT, including that it was fabricated by Arlen Specter based on the premise that only two shots had struck JFK and JBC. Specter's job was to present the SBT-LNT narrative, not to investigate the truth. The WC concluded that one shot struck near Tague.
That CE-399 was not found in Trauma Room 2 adds another layer of perplexity. Even then hospital procedures were to retain bullets and report bullet wounds to police. JBC recalls the bullet fell from his leg on clicked on the floor of Trauma Room 2.
Yet somehow a slug is found in the Parkland hospital corridor, described as a "pointy-head" slug by OP Wright, hospital administrator and former police chief, and then that slug is purported to be CE-399.
I have reasonable doubts about the LNT-SBT.
Take away CE399 and there is no issue with the SBT.
The only reason Shaw and Gregory doubted it was because they were trying to account for CE399 as the bullet involved.
Both JFK and JBC getting shot through by a single bullet fired from the SN is to be fully expected given that it passed through nothing but soft tissue until striking JBC's ribs.
As you point out, the bullet (fragment?) in JBC's leg fell onto the Trauma Room floor and was picked up by a nurse. Henry Wade, visiting his good friend at the time, reports the nurse coming up to him and asking him what to do with the bullet. He told her to give it to a policeman. She put it in an envelope and gave it to officer Bob Nolan who eventually put it on Fritz's desk.
While all this was going on, Audrey Bell was placing the small bullet fragments retrieved from JBC's wrist into a small plastic box and envelope when two FBI agents came in and confiscated the fragments. Miraculously, while it was in the FBI's Washington Labs, the bullet left on Fritz's desk by Nolan morphed into the small bullet fragments taken from JBC's wrist. The same miracle morphed the pointed "hunting slug" found by Tomlinson into CE399, also in the Washington Labs.
Hmmmm...
The bullet that passed through JFK and JBC at z222/223 fragmented when it struck JBC's radius.
This accounts for the various holes in the clothing and why there is no hole for a bullet to pass through in the X-Rays of JBC's wrist. It explains why there is no metal fragments from this bullet found in JFK or JBC until the wrist then leg.
