Grease, dirt and grime adhering to the sides of the magazine well can prevent the clip from falling out properly after the last cartridge is chambered. It's This has been known for quite some whilw. Lattimer brought it to the attention of the JFKA community in Kennedy and Lincoln back in 1980.
But it is a fact that the clip was slowly falling out as detective Day handled the rifle...That means the clip was NOT hung up in the magazine.
"Slowing falling out" is due to what Lattimer and others found, that the clip doesn't fall out properly. You have characterized that as the clip being jammed.
"Further tests were conducted by loading four cartridges into the CE375
cartridge clip and inserting it into the magazine of the rifle. The cartridges
were worked through the rifle's mechanism and ejected without being fired.
When the last cartridge was chambered, the cartridge clip remained in the
magazine instead of falling out as it is designed to do."
— VII HSCA 365
2.) In the Carcano, ejection is powered by the cycling of the action. Because of that, the force applied by the ejector against the cartridge rim is directly proportional to the force being used to pull the bolt backwards. If you pull softly, you wont get much ejection out of your ejection.
Yes it's true the spent shell ( or live round) can be prevented from being ejected by refraining from pulling the bolt back all the way or pulling the bolt slowly to the rear.... But that's not what Capt Fritz did....He pulled the bolt back in a rapid motion and the live round merely fell out of the rifle....I
They were examining a piece of evidence, not at a competition meet. Fritz would pull the bolt back as gently as possible.
It was NOT ejected by the ejector. Which means the cartridge was not married to the face of the bolt....That live round had simply been dropped into the barrel ..... It had not been stripped from the clip. The elevator lever scratches the last round in the clip but there was no elevator mark on the live round. The reason.... That Live round was not fed to the bolt by the elevator lever.....
"After examining the CE 141 cartridge found in the chamber of the CE 139
rifle, the panel concluded that it had in fact been worked through the action
of that rifle from the magazine."
— VII HSCA 379
Figure 20.—Photomicrograph showing the correspondence between the
individual identifying characteristics on the side of the CE 141 cartridge (L)
and on panel unfired test cartridge No. 4 (R), produced by the magazine
follower of the CE 139 rifle.