Firstly no matter what your view of the South African justice system I think anyone would rather face trial in SA than Zimbabwe or Equitorial Guinea. However it does seem rather absurd that the Scorpions are charging two people that have been released by the Zimbabwean authorities
I'm sure the Scorpions would be better served fighting global terrorism - as in investigating what Al Qaeda links there are to SA (seems there are some with these chaps arrested by the Pakistan authorities) than worrying about some alleged coup in a far flung corner of Africa that wont affect any SA citizens.