Topic
Can anyone respond to a workflow task in Office 365?
Instructions
Yes, any user account within the SharePoint Online environment, that has Contribute permissions on the task list, can respond to a workflow task, even if it is not the user account to which the task is assigned.
Additional Information
To work around this behavior within Office 365, a Nintex Task Form can be applied to the associated workflow task and a disable rule can be applied to the controls on the form that would prevent any user account that is not the assigned user account from responding to the task.