This has come up in this question. The answerer, Clint Black, is the official brand manager for Savage Worlds, and (when their forum is up) he is responsible for all official rules clarifications and corrections. I believe the user is the person claimed, otherwise they went out of their way to find an actual photo of Clint in order to impersonate them. However, others may well disagree, and one commenter has asked for additional evidence of the fact, with some kind of citation.
So a couple of related questions:
To what extent do we go on trust that a named user known within the RPG community is who they say they are?
When that user has official responsibility for rules questions and clarifications, how should they evidence their answers? This is especially an issue when an answer is a clarification that does not exist in published material.