code:hilite and indentation correction depends on paren shape?

In the following example, why does the second form typeset differently than the first? Could we change the second to match the first, or would this be a breaking change?

#lang scribble/manual

@(racketblock
  ; indentation correction works as desired:
  (foo bar
       (code:hilite [define baz
                     (get-baz bar)])
       baz)
  ; indentation correction does not work:
  (foo bar
       (code:hilite (define baz
                      (get-baz bar)))
       baz))

Start by running the provided #lang scribble/manual example and compare the two racketblock forms using code:hilite. Trace how the bracketed and parenthesized forms apply indentation correction, then determine whether making their output match would change existing behavior; done means the behavior is explained and the compatibility impact is documented.