I have read through the above and can not see why you believe this to be a case of racial discrimination?
May I ask what reasons (or even better evidence..) you have to think it is racial discrimination?
My suspician, and i say this very respectfully (and without any knowledge of you personally!) is the powers to be dont like you much. Usually in companies the people who are well liked do not get disciplined very often. You will probably find company policy allows for much discretion in the handing out of official warnings. But if you were only sent material and did not forward it on, deleted it etc then you have arguable grounds to overturn the warning. As other have said, the companies email protocols and policy would be a good starting point to that end.
If you do have any evidence to suggest racial discrimination then I suggest you pursue it through the NSW Anti - Discimination Board or it's federal counterpart the Equal Opporunity Commission. Believe me that if you file an application/complaint, the company will take notice and the people handing out warnings will be noticed by their bosses. The staff at the Anti-Discrimination Board are helpful and should be able to assist you with any enquiries.
http://www.lawlink.nsw.gov.au/adb
(Please note their are reasonably short timeframes in which you can make a complaint, so do it quickly should you intend to.)
Anyway, some light reading below:
Anti-Discrimination Act 1977 No 48
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7 What constitutes discrimination on the ground of race
(1) A person (the perpetrator) discriminates against another person (the aggrieved person) on the ground of race if, on the ground of the aggrieved person’s race or the race of a relative or associate of the aggrieved person, the perpetrator:
(a) treats the aggrieved person less favourably than in the same circumstances, or in circumstances which are not materially different, the perpetrator treats or would treat a person of a different race or who has such a relative or associate of a different race, or