that s beacuse his GPA is >2.. if GPA<2 ,then staus will be under prob.

Well its a pass because it is graded (in that you score a point for the grade) ,earlier on,like 2 years back anything below C was 0 point.So that new grading system was introduced to "help" us avoid being under prob,but still do re-sit or do supp.
In fact if that subject in which you scored D is pre-requisite for any other subject,i doubt you will be bale to register fpr the latter subject.(I THink,not too sure),,But bottom line any score of D for core subject,is for sure re-sit!

Yup,thats basically it! hope your results was all good btw...Sigh,,havent seen mine yet,barred by finance! Im praying to GOd im in the pass(above C),coz already have 2 MC im studying for right now.no holiday me !