History Matters reports that Captain Humes retracted the autopsy
report’s placement of the fatal entry wound during his testimony of
September 7, 1978 and allowed his revision to stand until 1996.

Source:

http://history-matters.com/archive/contents/hsca/contents_hsca_vol1.htm

"The second day of testimony related to the medical evidence and analysis
in the case. Much of this was presented by Dr. Michael Baden, head of the
HSCA's nine-member Medical Panel. This day also saw the testimony of Capt.
James J. Humes, the lead prosector at the autopsy of President Kennedy.
Humes publicly retracted the autopsy report's placement of the fatal entry
wound, which the Medical Panel determined was 4 inches away from the
originally-noted spot. In 1992 for the Journal of the American Medical
Association, and again in 1996 before the Assassinations Record Review
Board, Humes retracted this retraction."

In reality, Captain Humes and Commander Boswell retracted the placement of
the fatal entry wound during their joint testimonies of September 16,1977.
Humes retracted his retraction on September 7, 1978.

Source:

http://history-matters.com/archive/jfk/hsca/reportvols/vol1/html/HSCA...

"Dr. HUMES. . . . So, I saw them on that occasion. I saw them again on the
27th of January of 1967 when we again went to the Archives and made some
summaries of our findings. I go back further to the original autopsy
report which we rendered, in the absence of any photographs, of course. We
made certain physical observations and measurements of these wounds. I
state now those measurements we recorded then were accurate to the best of
our ability to discern what we had before our eyes. We described the wound
of entrance in the posterior scalp as being above and to the right of the
external occipital protuberance, a bony knob on the back of the head, you
heard Dr. Baden describe to the committee members today. And it is obvious
to me as I sit here how with this his markedly enlarged drawing of the
photograph that the upper defect to which you pointed or the upper object
is clearly in the location of where we said approximately where it was,
above the external occipital protuberance; therefore, I believe that is
the wound of entry. It relative position to boney structure underneath it
is somewhat altered by the fact that there were fractures of the skull
under this and the President's head had to be held in this position thus
making some distortion of anatomic structures to produce this picture."

"By the same token, the object in the lower portion, which I apparently
and I believe now erroneously previously identified before the most recent
panel, is far below the external occipital protuberance and would not fit
with the original autopsy findings."