If the scan shows a bad speed sensor then there where lies the problem, I would suspect. (It's an easy change out) But, as you stated, they didn't say which one !
However don't over look the bent lines, this is probably not the cause of the tranny being in limp mode but depending on how bad they are bent you may not be getting suffiecently cooled fluid back to the tranny.

Just my Dos Centavos

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