Graves believes Max Holland.
Holland was trying to reconcile the SBT with the overwhelming evidence of the 1.....2..3 shot pattern. It can't be done. In his attempt to do that, he had to overlook the evidence that the last two shots were in rapid succession (5 seconds (z223-z313) doesn't fit that evidence) and that virtually everyone said that the first shot occurred at a point well after Zapruder started filming the motorcade cars.
The 1.....2...3 shot pattern cannot be reconciled with the SBT, but it does fit with Oswald firing all the shots.