My guess is that Google requested use of the Metaphone 3 package, Lawrence perhaps didn't understand the what BSD meant, but was willing for Google to use it in their Google-Refine (now Open Refine) codebase so willfully let them pick the most permissive license.
I'm having a real difficult understanding him from his GitHub comments. It's clear that he never intended his algorithm to be re-useable or modifiable in any way, but if he intends to restrict the future use of his Metaphone 3 code or even prevent a port, he's going to find it impossible....
Lesson learnt... it's clear that a work of this magnitude would have taken thousand plus hours... if you don't intend it to be re-usable, then you shouldn't pick a permissive, open source license such as BSD.