In the opening scene, Vance Logan (Lou Rawls) is singing and playing a guitar, but his hands strumming the guitar do not remotely match the sounds the guitar is making.
The doctor tells Mannix that Vance has a very rare blood type (AB+) which means that he can only accept transfusions of AB+ blood . Any doctor knows that AB+ is the "universal recipient" which means that any type of blood can be transfused, not just AB+.