Confusing an explanation by an excuse

Refer to confusing an explanation with an excuse. You attempt to defend a claim by explaining it in more detail, concluding that it is therefore true.

For instance - defending the claim that Bigfoot is the missing link between great apes and humans by explaining what a 'missing link' is.

It also happens when someone interprets an explanation as a justification of a fact/possible fact. This version of the fallacy is very common in political debate.

Xavier: Gender roles may have developed as a result of biological differences in the sexes, rather than because of some sort of deliberate, top-down, patriarchal system.

Lars: So...you're saying that it's okay for women to be oppressed because of their 'biology'?

(Notice Lars also committed a strawman fallacy).

To prevent it, move away from explaining what a claim means, and move towards providing independent evidence for it.