If there is enough doubt to suggest that AJ or others may have committed perjury and perverted the course of justice then the senators need to get them back.
If you want some parallels look at the News of the World inquiry in the UK. Andy Coulson is facing if not already charged with perjury for misleading that inquiry.
Geoffrey Archer served 2 years in prison for pejury and lost his knighthood.
So this could get very interesting!