It is possible that they are investigating if it is possible to fix the issue and what it would would cost them to do so before making any public announcement. If it is technically impossible or too expensive to fix, they have no reason to expose themselves to liability by admitting the error. There is also the (likely) scenario that they investigated the issue and found it impossible/too expensive to fix some time ago, but decided to release on PSN anyway to maximize profit. Again, that would mean that they have no reason to expose themselves to liability by admitting the error.
Rockstar appreciate the onetime sale to the casual consumer, but what the absolutely love is the staggering per consumer profit of selling a broken version of their game (PSN), a somewhat less broken version (PS3 disc), and finally the complete working game (PC, PS4) to hardcore gamers. If they are really lucky you will pay full price for all of these versions and possibly a double set of their dlc too! Sure, the causal sales probably make up the lion share of the actual profits, but releasing a good game and having people pay just once for it is for loser companies like Ubisoft and Activision ...