The post reminds me of one of my favorite scenes from a Hitchcock movie (which I transcribed a while back, knowing it would be useful at some point in the future).

In Hitchcock’s 1938 movie The Lady Vanishes, the heroine Iris Henderson is traveling on a train in the same compartment as an old lady. When the old lady disappears (it later turns out to be connected with a spy ring), Iris scours the train in search of her. She meets a German doctor named Dr. Hartz, who accompanies her on her search for the old lady. But when everyone denies having seen the old lady, Dr. Hartz theorizes that some psychological hallucination must have caused Iris to imagine the old lady’s existence.

But then, finally, Iris finds one woman who admits to having seen the old lady. Iris then confronts Dr. Hartz with this new witness:

“You’ll have to think of a fresh theory now, Doctor.”

"It is not necessary,” Dr. Hartz responds. “My theory was a perfectly good one. The facts were misleading."