όξω πούστη απ' την παράγκα!

[Theseus]

I'm a bit stuck on the writing in bold. Is this now a common or outdated expression?
όξω πούστη απ' την παράγκα!
Ατάκα που καθιέρωσε η αείμνηστη Μαλβίνα Κάραλη για διαπόμπευση κι εξοβελισμό δημοσίων προσώπων, συνήθως πολιτικών, που διαπράττουν σοβαρό ατόπημα.
- Ο Κούγιας έχει ως γραμμή υπεράσπισης του πελάτη του αστυνομικού την δυσφήμηση του νεκρού δεκαπεντάχρονου.
- Όξω πούστη απ' την παράγκα!
Does this mean 'Kougias has as his line of defence the slander of a man who died fifteen years ago and was a regular at the police station?'

 

[nickel]

You can hear this sound bite used by Karali at the end of a short video from an end-of-season TV broadcast in 1997 here. Karali died in 2002.

The example used by the slang.gr member in your entry is more recent and is related to the trial of police officer Korkoneas, who shot 15-year-old Alexandros Grigoropoulos in 2008. Kougias was the policeman's defence attorney. The example above means that Kougias used as his line of defence the slander of the dead fifteen-year-old.

 

[Theseus]

Thanks, Nickel. What exactly does του πελάτη του αστυνομικού mean? It seems otiose.

 

[nickel]

Sorry, missed that. Of his client, who is a policeman.
It could have been: ...ως γραμμή υπεράσπισης του πελάτη του, του αστυνομικού, την ...

 

[Hellegennes]

Sorry, missed that. Of his client, who is a policeman.
It could have been: ...ως γραμμή υπεράσπισης του πελάτη του, του αστυνομικού, την ...

It should have been; otherwise it is "ο πελάτης του αστυνομικού".