Cards on the table
Hercule Poirot (David Suchet) says at one point, "The question is, can Hercule Poirot possibly be wrong?"
"No one can always be right," Mrs. Lorrimer replies.
"But I am! Always I am right. It is so invariable it startles me. And now it looks very much as though I may be wrong," laments Poirot, "and that upsets me. But I should not upset, because I am right. I must be right because I am never wrong."