Rationale:

This is editorial. Both "throws" statements are true. The bug is just that the second one should be a sentence, part of the "Effects" clause, not a separate "Throws". The project editor has been notified.

[string.replace] basic_string::replace, second signature, given in paragraph 1, has two "Throws" paragraphs (3 and 5).

In addition, the second "Throws" paragraph (5) includes specification (beginning with "Otherwise, the function replaces ...") that should be part of the "Effects" paragraph.