User blog comment:Lambda1/"We Happy Few" - Discussion/@comment-26992577-20160524215123/@comment-34326521-20160524222915

You're still making an assumption. Namely, that the writers suffer from retrograde amnesia and forgot that Amara is nigh-indestructible.

Occam's Razor states that, all things being equal, the explanation with the least assumptions tends to be correct. However, failing that, we must see how reasonable those assumptions are.

Your assumption: the writers forgot Amara is nigh-indestructible and made a mistake, despite said mistake being on the episode that serves as a set up for the plan to defeat Amara.

My assumptions: the writers thought they were being clear in their intentions, but weren't.