For example it cannot process this date string: 2014-10-01T13:11:27.000+02:00
It fails in parsing the seconds as it tries to convert '27.000+02' to an int.

A possible replacement for the entire try block would be DatetypeConverter#parseDateTime.
(http://docs.oracle.com/javase/6/docs/api/javax/xml/bind/DatatypeConverter.html#parseDateTime%28java.lang.String%29)
See http://stackoverflow.com/questions/12201233/convert-iso8601-string-date-time-format-to-date-in-java

You can reproduce this by:
Opening the JCRBrowser to /demo-project/news-and-events/events-overview/new-year-s-eve@dateEnd
Switch type to a string.
Switch type back to a date.
It will now show the current date since the string to date conversion failed.