So there's some kind of filtering going on, for whatever reason.
My guess: someone created a list of addresses, sorted it, and copied a part of it to be funded. I don't think there's much more behind it.
Occam's razor? I guess so, although it would seem more likely if only a single address (say, for change) was the odd one out.
Just for fun, I quickly hacked together something to generate four random words and filter the output so that the first bytes of the address are b0, 9a, 09 (which match the last passphrase I mentioned in this thread). The same could be done with real-world phrases if you had a sufficient number of them. A crude form of SHA256 brainwallet vanity address generation.
1H6nTM5TVQc31YqhVzVPrRUmNsL9pGJAwV b09a091fccb7e1f2f0a8120f3e17117a79759920 "captaining financial conservatism mayonnaise"
1H6nTPYd9sKto7bn7ptVqGWzD3mUdByNMy b09a0947f10d65c58ad6f7bc551b85d6d399b3b5 "gladiator playmates reduction disseminates"
1H6nTZUuqwmwKy6C64UK5jAdZATAMfpasK b09a09e9865339e6a5beabd64682380bd7862fd3 "physicists rottenness displaces processed"
=== ADDED LATER ===
Here's some real-world phrases which happen to match the simple vanity address requirements from above. I forgot about it and left things running for longer than I should have.
1H6nTagcotDzbyM3W3ymWRBRcwuJV1Cpvd b09a09fd11c309d6ae2321406c3cd8540cee9174 "scott and andrea"
1H6nTRxrjZ3PiiPvwLwegQFrtBURsKvjUo b09a096f42e5efd99614509be6625e7c1119b539 "colonel edward mandell house"
1H6nTUtXkLPgU36ufJeVEpTmPvbVGXLypV b09a099ed5ce28e7f241ce53893045ad88d48da3 "never gonna be as big as jesus"
(Note: These are examples from my vanity generation experiment, not actual cracked passphrases.)