MAC: UE4 Editor crashes in gldReadTextureData on Nvidia 330M

A user is reporting semi-regular crashes on his MBP 6,2, with Nvidia 330M GPU. This is a GL 3.3 GPU which we don't routinely test against, he may have the 256 or 512MB model, but this is unclear. The crash occurs within creation of a uniform buffer, which flushes the MTGL command stream - the crash actually occurs in a deferred texture-readback inside the driver function: gldReadTextureData

I was in the top down orthographic view attempted to click the icon in the upper right of the screen to return to prospective view, then it crashed.