Now there's an interesting concept. You feel the patient is haemodynamically stable with no associated blood loss, yet he still has a persistent tachycardia (never mind blood from his leg is dripping on your shoe's. You cap off those intravenous cannulas (don't really know why you placed them in the first place).

Your boss walks in just as you slip on that expanding pool of blood. "Ah - er - Oh hello sir, just checking this man's blood group - ha ha - er ha?".
"Nurse - get this man some new clothes - something that'll keep him warm on the streets." It seems you've been fired. Still - it's not a bad overcoat.