This title is click-bait. It sounds like it's talking about comets picking up life from one planet and delivering it to another, but that's not what the article

This title is click-bait. It sounds like it's talking about comets picking up life from one planet and delivering it to another, but that's not what the article (and paper) says. They're just talking about space-generated biomolecules being delivered to planets (as has been found on Earth); the only "bouncing" involved is a comet losing energy by going through gravity wells in a dense planetary system.