Detached
I was riveted to my father's agony.
No, the opposite of a definition is certainly not always true. That would depend on the definitions and the meaning of the opposite.
it is riveted in.
Undefinition
specific
what is the opposite of brooding
opposite
The opposite of download
I found myself riveted as I listened to the speech.
Generosity, possibly.
Adjacent
Lady GaGa's costumes are so gaudy that many people are riveted by her.