Aha, now Devel::Peek output has some evidence: 
OK:
SV = PV(0x35b92f0) at 0x34adca8
  REFCNT = 1
  FLAGS = (PADMY,POK,pPOK,UTF8)
  PV = 0x35b8970 "Hello \342\200\223 World"\0 UTF8 "Hello \x{2013} World"
  CUR = 15
  LEN = 24
SV = PV(0x35b92c0) at 0x34ada98
  REFCNT = 1
  FLAGS = (PADMY,POK,pPOK)
  PV = 0x35b8580 "\"Hello \342\200\223 World\""\0
  CUR = 19
  LEN = 40

CRASH:
SV = PV(0x35b9250) at 0x34b3030
  REFCNT = 1
  FLAGS = (PADMY,POK,pPOK,UTF8)
  PV = 0x35b8950 "Hello \342\200\223 World"\0 UTF8 "Hello \x{2013} World"
  CUR = 15
  LEN = 24
SV = PV(0x35b90a0) at 0x34b30d8
  REFCNT = 1
  FLAGS = (PADMY,POK,pPOK,UTF8)
  PV = 0x2f7fb60 "\"Hello \342\200\223 World\""\0 [UTF8 ""Hello \x{2013} World""]
  CUR = 19
  LEN = 40

In reply to Re: JSON::XS produces valid utf-8, and JSON doesn't - why? by isync
in thread JSON::XS produces valid utf-8, and JSON doesn't - why? by isync

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.