1st time on my spinal immobilization/LSB practical, I failed due to the C-collar. I was nervous, and the c-collar was across the room, so I couldn't see it, and didn't think about it. I had my partner maintaining C-spine, while putting the PT on the LSB, and then saw the c-collar over by the wall. Talk about the 'Oh crap' moment... So while I didn't fail due to the loss of c-spine control (partner was maintaining), I hit the critical fail of 'performing as a competent professional blah blah blah'. Luckily I was able to re-test the same night and pass completely.
Moral of the story: before you get into the actual pt. care, do a scan and make sure to do a quick scan and see that you have ALL supplies needed, and lay them out where you can see