The self-defeating knight is an article in Resident Evil Recollections. It was uploaded on 5 November 2015.
Steve attempts to operate a crane in the Antarctic Base in order to free a tunnel borer, but he ends up daydreaming at Claire, and breaks a pipe which floods the room with poisonous gas.
The pair flee the room, with Steve admitting that it's "all his fault", although to be fair it's hard to blame him really.
I've adopted the phrase myself at work for when I mess up in spectacular ways!