The paper tests this hypothesis and finds that there's probably a causal effect:

"...these results demonstrate that the screening effect may have played a role, but it appears insufficient to entirely account for the observed difference between near misses and narrow wins."

Or researchers who had near misses are at institutions (or moved to institutions) that have sufficient internal resources to get early career researchers bridge funding to keep them productive during their funding lull.

I think there are so many ways for people to get lost in the current finding environment, that would be extremely difficult to be able to make any findings to how people performed. The main exception I see is the attrition rate. This is the measure they reported that I have the most confidence in.

As was said elsewhere, everything else just smalls of a survivorship bias.

+1. The dual populations of dropouts and higher performers smells like survivorship bias.