One more thing I will add ... search in Lenovo's site for any update to your webcam's driver. Search by ThinkPad X1 Carbon, 20BSFVT013.
The applied driver is of Sept, 2014.
If no update is found, downgrade it if possible. See how it goes.
If still the same BSOD continues, disable the webcam as a test at least, see how it goes.
Let us know.