I don't know that much about the situation, but this seems like the same question I've asked myself over and over about what the US gets out of having secret prisons and using torture to get information that is likely faulty and outdated at best--and making it public. On this, I think this assessment by Naomi Klien assessment is pretty close:
http://www.thenation.com/doc/20050530/klein
In this case, it would seem that it is a draw whether it matters more for Putin/Russia to have a pristine image abroad or a reputation for being a hardass at home. The latter seems to be a more regular concern but that is not close to being enough evidence: it just casts some doubt on the cost/benefit argument offered here.