Looks like an IPTC encoding mismatch to me. I guess the website uses a different character code for the apostrophe; both ' and ’ are used and show up differently using different fonts. The first one is a "normal" ASCII character which has the same character code in almost all encodings, the latter actually is encoded differently depending on the encoding (e.g., Mac, Windows Latin 1, etc.)
Note: this only holds true for IPTC embedded info, not for XMP info as that always uses UTF-8 encoding and hence has no encoding problems.
Cheers,
Hayo