alt Hacker NewsLower cost usually means lower quality and is an example of how a long path being leaked can result in traffic flowing away from high quality path to the leaked path.
Not saying that this is the case with Venezuela, just explaining the reality of BGP where path prepends are often ignored.
His claim-- as best as I can read it-- is that B leaking a long-length route changes where traffic is routed, but not to B.
It's possible he's saying something else, but I can't figure out, and he hasn't clarified.