Links from the BBC have, historically, been some of the most important links that a website can get and there can be no doubt that Google rates the BBC as one of the most trusted sites on the web.
The links used to be direct links but they are now passing through two redirect scripts using a 302 redirect which is highly unlikely to pass any PageRank.
Don’t know if I’d use “greedy” as an adjective. “Unthinking,” probably. I imagine what’s happened is that this has been done without any thought to sites being linked to, and this was no doubt the easiest way of counting clicks out of the site (Yahoo! does the same, or at least used to, from a lot of its pages).
What it does signify is the BBC’s singular lack of awareness of what its digital footprint is, in terms of its interconnectedness with the “non-BBC web” (and I bet a lot of people over there think of it as the “non-BBC web”, too). Somebody at the Big British Castle should have thought “hang on, we can give Google juice to other sites, and we can celebrate it too, and that would be good for the BBC and good for British web publishing.” The fact that no-one had that thought, apparently, is what we should be dissing the Castle for, not what looks like rather a clumsy technical implementation.