Yes, they are, they show as a dead thumbnail when the error occurs, so its easy to track it down just at a quick glance, but, its not always that easy, if the file is near completion, the thumbnail will look it too 
Keep forgetting, the only thing on my mind is get wd running as quick as, everything else is a blur
What i could do a bit later on is try and manually force it to occur
The only issue i have come across with this method (i will put a disclaimer up) is that if WD loads before webcamcapture, your webcam image in wd mainscreen disappears for short time until webcamcapture starts up, then the next part of this issue is, the image reverts to is default size (big) this then stays like that until WD is restarted.
2 ways to look at the above, its just creating another issue or, its actually a fix until you are back at your machine (if it was an auto restart or start from power fail) and upin seeing the larger image knowing that an error occurred and wd happily started up with out incident.
There is a workaround for the above issue, many of you use start watch, just have WD delay start 2 mins after startwatch, have webcamcapture start 15 seconds after startwatch, it does not need WD to run so all will be well and it will produce the image that the PC deleted upon start up, it needs 15 seconds because it needs a little time for the startup to delete the image(s) 1st.