You're right. I got very confused while writing. Let me restate things.
When both an indirect object pronoun and a direct object pronoun occur in the same phrase, the indirect object pronoun precedes the direct object pronoun.
The indirect object pronoun (
le for 3rd person) changes to
se if both objects begin with the letter
l.
In
se le devuelva, the second pronoun (the direct object pronoun) is technically incorrect. It should have been
lo, unless you're in certain regions where
leismo is accepted. The direct object pronoun refers to the kidney (so,
le refers to the kidney). It is perfectly good Spanish to use a direct object pronoun and then turn right around and say the direct object in the sentence.
But, it was about at this point where I got mixed up. I was thinking about the
leismo and then messed up everything.
My apologies.
