Its not just him. After 10.9.2 update, mine crashes as well. Steam version, 2011 MBP, 6750M
I'd contact Feral support and we can have a look, we have thousands of users and (so far) a small handful reported instances of problems, it could grow by a few but it is still likely due to a specific setup issue not the game itself. With every OS update a few issues always crop up as the OS update process isn't perfect and sometimes something goes wrong. Usually it's an easy fix for the user once they send over their details and we can see what the issue is.
FYI we have been testing on 10.9.2 with Tomb Raider for months now as the internal benchmark was used a lot to verify OpenGL improvements by Apple. The AMD 6000 series has had a few hundred hours of gameplay in 10.9.2 so we should be able to work out what's wrong with your setup and get you playing pretty quickly.
As an aside the performance should improve in 10.9.2 as there have been some pretty substantial changes to OpenGL.
Edwin