Note that they always ask that you do not designate the donation for any set disaster fund, but rather to general use, so they can do what they danm well please with it.
I figure that if I sent in money tagged for "whatever" they would just subract the amount they would have sent otherwise to help others.
From what I can tell the relief is done by nearby congregations with THEIR funds and manpower. The most the borg does is keep track of who is doing what where and then taking credit. I have never seen an actual check or recepit for anything the bigwigs did.