I do stand to be corrected but I have also heard from Nationwide's engineers that after SAFAIR released the aircraft back into service nothing significant was found on any of NTW's aircraft that warranted grounding them outright in the first place.
If that is in fact true then that would in my opinion prove that the whole grounding was a bit of a knee jerk reaction on CAA's part. Fact is that none of the aircraft where in perfect condition when they left SAFAIR's hangar, still plenty of snags and defered items. Most NTW pilots will tell you that generally the condition of the aircraft was not any better, if not poorer after the grounding than before it. Whats the point of forcing NTW to outsource its maintenance then?
I do think there was some political motive to shut NTW down. Whatever was wrong could've been fixed. Guess we'll never know.