Please beware that the column property seems almost always to be invalid. I thought it only occurred when the line in question was long (and I was just about to submit a bug report with an example), however, at the time of posting, you can even see the problem in the example provided on this page: line 4 does not even have 46 characters. Where the XML line is long, the difference can be very large.
This property comes from the libxml extension, so in any case I don't think this is a PHP bug, however it is worth knowing that the value might be totally unreliable to save some confusion.
The PHP documentation page for the libXMLError class gives some indication, stating:
"This property isn't entirely implemented in libxml and therefore 0 is often returned."
(My libxml version: 2.9.1)