The code below is being added to taskresult nodes somehow. I haven't looked into it very closely at all. It's javascript and probably embedded within the taskresult control itself which is unfortunately hidden from you. I wasn't able to find a switch to disable that so a way around would be to not use the taskresult control. Otherwise look at the nodes maybe and see if there's a switch somewhere.
this may be of some interest to you as well
ESRI Server Forum
esriContextMenus['Results_TaskResults1_removeOnlyContextMenu'] = new esriContextMenuObject('Results_TaskResults1_removeOnlyContextMenu',...