View relationship gives ajax error without edit contact permission

sIt seems that after upgrading to 4.5.5 if a user just has view permissions on a contact, but not edit, they get an ajax error when attempting to view a contact's relationships. This error does not appear to occur in 4.5.4.
Here is a network trace:
URL Protocol Method Result Type Received Taken Initiator Wait‎‎ Start‎‎ Request‎‎ Response‎‎ Cache read‎‎ Gap‎‎
/administrator/components/com_civicrm/civicrm/packages/jquery/jquery-ui/images/ui-bg_glass_75_dadada_1x400.png HTTP GET 200 image/png 0.75 KB 31 ms background-image 53937 0 16 15 0 2079
/administrator/?option=com_civicrm&task=civicrm/contact/view/rel&reset=1&cid=1009&snippet=json HTTP GET 200 application/json 6.97 KB 438 ms XMLHttpRequest 55062 0 438 0 0 547
/administrator/components/com_civicrm/civicrm/i/loading-overlay.gif HTTP GET 200 image/gif 4.82 KB 15 ms background-image 55078 0 0 15 0 954
/administrator/?option=com_civicrm&task=civicrm/ajax/contactrelationships&context=current&cid=1009&sEcho=1&iColumns=11&sColumns=%2C%2C%2C%2C%2C%2C%2C%2C%2C%2C&iDisplayStart=0&iDisplayLength=10&mDataProp_0=0&bSortable_0=true&mDataProp_1=1&bSortable_1=true&mDataProp_2=2&bSortable_2=true&mDataProp_3=3&bSortable_3=true&mDataProp_4=4&bSortable_4=true&mDataProp_5=5&bSortable_5=true&mDataProp_6=6&bSortable_6=true&mDataProp_7=7&bSortable_7=true&mDataProp_8=8&bSortable_8=false&mDataProp_9=9&bSortable_9=false&mDataProp_10=10&bSortable_10=false&iSortingCols=0&_=1420309678919 HTTP GET 500 text/html 4.15 KB 422 ms XMLHttpRequest 55562 0 422 0 0 63
/administrator/?option=com_civicrm&task=civicrm/ajax/contactrelationships&context=past&cid=1009&sEcho=1&iColumns=11&sColumns=%2C%2C%2C%2C%2C%2C%2C%2C%2C%2C&iDisplayStart=0&iDisplayLength=10&mDataProp_0=0&bSortable_0=true&mDataProp_1=1&bSortable_1=true&mDataProp_2=2&bSortable_2=true&mDataProp_3=3&bSortable_3=true&mDataProp_4=4&bSortable_4=true&mDataProp_5=5&bSortable_5=true&mDataProp_6=6&bSortable_6=true&mDataProp_7=7&bSortable_7=true&mDataProp_8=8&bSortable_8=false&mDataProp_9=9&bSortable_9=false&mDataProp_10=10&bSortable_10=false&iSortingCols=0&_=1420309678920 HTTP GET 500 text/html 4.15 KB 438 ms XMLHttpRequest 55609 0 438 0 0 0
/administrator/components/com_civicrm/civicrm/packages/jquery/plugins/DataTables/media/images/sort_both.png HTTP GET 200 image/png 1.60 KB 15 ms background-image 55625 0 0 15 0 407