When Harold Weisberg examined high-quality photos of JFK's shirt at the National Archives, he noticed there is less blood inside the collar band than on the outside, which doesn't fit the SBT scenario. If a bullet had exited the throat, one would expect there would be just as much blood, if not more, on the inside of the collar band as on the outside of it. Not only did Weisberg find this is not the case, but he also discovered that where the sides of the shirt overlap, there is no blood at all:
This is less blood inside the collar band than on the outside of the fabric, not consistent
with the bloodstains coming from the body side. Where the sides of the shirt overlapped
in wearing, no blood. (Post Mortem, p. 347)
Weisberg also found evidence that confirmed the belief that the slits were made by the emergency room nurses as they cut away the president's clothing--he could see the zigzag mark of a cutting blade on the slits:
The dead giveaway of the fabrication that this is where the magical bullet must have exited,
according to the official story, is the nonmagical, mute evidence of the slit on the left side.
The irregular, zigzag mark of a cutting blade is visible with an engraver's lens no more powerful
than the 10-power miniature I carry. (Post Mortem, p. 347)
One of the nurses confirmed this to researcher Henry Hurt, and Dr. Carrico told Weisberg that the throat wound was above the collar and that he did not notice any nick in the tie or slits near the collar before the nurses began cutting away JFK's clothing.
Dr. David Mantik likewise noticed the zigzag mark of a cutting blade in the front shirt slits. He also noted that there is no fabric missing from the slits, clear proof that no bullet or fragment created them.