The user apparently produced this result by typing "</nowiki >[[hello]]" into the editor, which Parsoid turned into "<nowiki></nowiki >[[hello]]</nowiki>", which is then parsed differently by PHP and Parsoid.

Also similar, adding "</nowiki>[[File:Example.png]] to a image caption in VE" results in http://en.wikipedia.org/wiki/User:AzaToth/sandbox/image and opening edit of caption again gives me http://i.imgur.com/PQVRoH6.png

I have a partial fix locally that needs more testing.

Change 74537 had a related patch set uploaded by GWicke:
Bug 51405: Recognize and escape nowiki with spaces and odd capitalization

https://gerrit.wikimedia.org/r/74537

Change 74537 merged by jenkins-bot:
Bug 51405: Recognize and escape nowiki with spaces and odd capitalization

https://gerrit.wikimedia.org/r/74537