But as Mr. Jack has explained, they would consider that to be a restoration of information that was there at creation. A mutation that could increase information beyond what was present at the beginning isn't possible.
But that is not really relevant. The creationist is arguing against *evolution* and *common descent* in a naturalistic framework by stating that mutations cannot increase information. We trivially demonstrate that they can. Stating that these mutations only restore information that was there to begin with is switching framework - this is no longer an argument against evolution, but a explanation of why we see information-increasing mutations within a creation framework. This is simply a slight of hand, and does nothing to defend against our demolishing of their original argument.