You can catch a bribery in action, and there can be many excuses defending the act. It could be justified as money lending, or pay back of a loan, or be a gift, for example . Hence, 'both' of them can get away. Though bribery is morally bad, a bit of justice lies in the word 'both'.
What about sex? If it gets exposed, the girl for the sake of saving her dignity may take an abrupt turn and scream 'rape', doesn't matter how madly she had been in 'love' with the unfateful boy (who won't be able to recover from the shock for the rest of his life).
The same could be a case with a greedy call girl, who might have decided to arm-twist a good money by black-mailing her clients and acting in collusion with the police. So it's girls who have lopsided advantage in any un-Islamic constitution, which off course is not Justice.
Compared to bribery one of the 'both' is left with extreme anger and a sentiment of left cheated.
Hence I find Islamic justice, pristine in this regard. If the accuser hasn't got any witnesses, he/she will be flogged 50 times. And if an unmarried couple is found having sex with each other, they 'both' will be beheaded (So that people do not have pre-marital sex only to have fun, then split and marry their prospective "to-be-husband/wife", only to spoil their lives and deprive them of virgin pleasure).
The pristine Justice of Allah!
