[VadeRetro]

That is fine. It is then part of the theory, and not a fact. That means you shouldn't use it as evidence for the theory.

That would depend on the reference of the pronoun "it." A cladogram contains details of relationships which in evolution are understood to be the product a historical diverging, branching process. Thus, a cladogram is only evidence that someone thinks the relationship is what the cladogram says. A fossil is evidence that an individual thing lived at a time.

[AndrewC]

Thus, a cladogram is only evidence that someone thinks the relationship is what the cladogram says.

Thus it is part of the theory.