Term used by domestic builders describing a deliberate error left on a job to distract from a far worse yet less obvious mistakes.
Bob the builder: Sorry about that bit of paint I got on your kitchen counter, Mrs Smith. A bit of turps should get that off.
( Mrs Smith smiles and signs the cheque, failing to notice only three of the four light fittings she has paid for are in place. )
Bob has used the paint spill as a designated distraction.