So I got this sentence where I needed to fulfill the personal pronouns [we MUST use a feminine pronoun since we are talking about a woman]
_____ dolían las muñecas y a los tobillos porque el chiflado _____ había atado a la silla y estaba sentada en una posición incomoda.
The uni teacher then gave us the correct answer:
Le dolían las muñecas y a los tobillos porque el chiflado la había atado a la silla y estaba sentada en una posición incómoda.
According to her explanation, the first "le" refers to an indirect object. I completely agree, since - "¿Dolían a quién? -> A ella".
But then the second example, where "la" refers to a direct object, seems more obscure to me.
I would have put "le había atado", because I ask myself "¿El chiflado había atado a quién?, había atado a ella".
Can somebody explain this confusion and give a technique for justifying these pronouns in the example above? I'm aware of leismo and loismo, but my question here is about traditional and conventional grammar.