If you are caught Airside with an expired ASIC then you will be escorted back to landside. If you make a fuss, you will probably instigate a paperwork trail that will get you fined. If DoTRS catch you, you will get fined anyway. The security guys (and some are goons I admit) are just doing their job. They are there to see that people are doing the right thing. If you knowingly display an expired ASIC you are not doing the right thing and deserve the consequences.
It is a condition of issue that expired ASIC's are returned to the issuing authority (see section 8 of the CASA Info sheet for Form 639), as in my companies case, the ASIC's are their property. If you have an ASIC, you have agreed to be bound by all this.
I know the system sucks, but we all have to live with it. I just got my renewed ASIC today (with 2 days to go - application, in full AGAIN, put in on 14th December). If it hadn't arrived, I couldn't have done my job. My company issues my ASIC. They are only following the stupid rules as well. There I am standing before them wearing a valid ASIC (that they issued), and I have to provide them with proof of ID (Passport/Birth certificate/Driver's Licence etc - all of which I produced 2 years ago to get my current ASIC) to receive my new one. When queried as to why wasn't my current ASIC good enough ID to use as it was sufficient to ID me Airside, they said that they don't make the rules.
That's the problem. The people who make the rules, not the ones who administer them.