"One is able to solve the problem by completing the sentence. He is taller than I am. Else, use He is taller than me. " Guest/ 8:09

That doesn't work, surely? One could say: He is taller than I (am), but not say: He is taller than me (am) or (is).

Colloquially, like most of us, I suppose, I say: Did you hear me knocking on your door? That was me!

Formally I say, Did you hear me knocking on your door? That was I!