I’ve said that for years. An asteroid or comet passing Jupiter has a chance to fling the projectile away from earth or towards earth. So many possibilities. The possibilities are unlimited actually.
A big rock coming into the solar system on the opposite side of the solar system from Jupiter means the Jovian mass has much less if any effect
Exactly. I think it's one of those wanna-believe things popularized in the foolish book Rare Earth, but then again, there are plenty of people who claim that any rock that may fall from space will burn up in the atmosphere of the Earth.
Vaquero, I’m curious as to why you think Saturn is not also a contributor. Is it because of the distance. Although next in order from Earth, it is still a lot farther out there than Jupiter. (These distances are stunning, really. But, minuscule in the scheme of the universe.)