The scenario: tutor was marking work submitted in groups, with a rubric (though I am not sure whether the rubric has much influence here). On most groups he forgot to click Save in the grading interface. This meant that even though he correctly released grades, and the grades and markings displayed for him in the grading interface (i.e. to some extent they were 'sticky'), those grades and markings didn't actually display to the affected students until he went back through and clicked Save for at least one piece of work in each group. After that, those students could view their grades and markings.
I am not sure if the problem is a lack of alert (e.g. "Please save your markings. Only markings which are saved will display to students when you release them.") or slightly misleading aspects of the interface.
I apologise for not being able to investigate the problem fully (it would take half a day to reproduce it), but it has come up previously.