I have no idea.
Of course you have no idea, no one knows for sure because it was never explained.
Because the WC never attempted to ascertain why this happened.
They accepted, sorry I made a mistake as all the evidence they wanted.
This was the greatest single investigation of an event in history, yet the WC negelected to explain how this misidentification happened.
Fact - Dallas Police discovered and identified a 7.65 Mauser with a Weaver scope on the 6th floor TSBD.
Fact - Re-identification changed to a 6.5 Carcano and cheap Japanese scope.
What rifle / scope was discovered?
There is no way to know for sure and if you guess it was a Carcano, you may be correct or you may be wrong. This is not, knowing, this is a belief, please try to understand this.
This is a crack in the wall.