An indignant justification or excuse that bear no relevance to what one is being accused of.
When I asked him if he committed the crime, he scoffed that it was impossible for him to have done so, because he was a well-regarded Hollywood director. I knew this was no more than a Polanski.
or
His Polanski for robbing the bank was that it was okay for HIM to do it, because he needed the funds to buy a pool and was otherwise a good person.
The child rapist was quoted as giving the following Polanski, "But thirteen year olds are so cute! And she had a vagina and everything. What was I supposed to do?"
The act of dressing up your partner to look like a thirteen year old boy/girl, committing unlawful sexual acts with that partner then fleeing the country in which the act was committed.
ex:
Brandon: Holy shit! Did you hear what Tosh did to his girlfriend?