Ok, while I agree, a tutorial is supposed to teach someone on how to make their own signature. He is in bounds, because of the fact that Bull3t told step by step how to make his signature.
Kinda like I can download Firefox's source, and then edit it and just edit everything that says Firefox into "Fireforce", compile it, and post it everywhere. Mozilla couldn't do anything about it, as long as I don't sell it (violates GPL, which I believe it's licensed under).
If the issue is morality of essentially duping his signature, that's between you two.