As discussed in this thread http://moodle.org/mod/forum/discuss.php?d=168266, but not yet posted here as far as I can see:

The workshop does not display the final grade to the student. The student can see the individual grades and feedback given by each assessor, and the final overall feedback given by the teacher, but not the final grade.

This final grade may well be overriden, which might lead to a scenario whereby the student works out their own average from the grades displayed, and is then confused later on to find that they actually received a different grade.

The final grade is shown via the Grades link, but it should really be visible in the activity itself.