Yes, but only if the kernel knows how to switch back to textmode. Knowing how to do that means knowing the state of the card and how to set up the registers for textmode. That means you need GGI to be able to see an oops while in graphics mode. (either you stay in graphics mode or switch out, but you still need the kernel support)
Sometimes people post "it crashes while running X" to linux-kernel. It is difficult to debug these problems when there is no oops data.