So far this has happened to me twice. Both times I was running around on my own on the Stratis Air Base landing strip, occasionally shooting and changing stances.
Suddenly screen went blank for a few seconds then came back online with a notification that my display driver crashed and game errored out with "D3D Error - DXGI_ERROR_DEVICE_REMOVED".
I haven't had any driver crashes before in any other game, including ARMA 2.
Logs, dumps, and dxdiag: https://dl.dropbox.com/u/34730455/a3/a3_gfx_crash.zip