Horses and zebras

Which approach seems right to you? How do you maintain a balance?

The standard advice is: “When you hear hoofbeats, think about horses, not zebras.”

It has a corollary: “But, if you hear hoofbeats and see stripes, think about zebras.”

But the patient with the atypical presentation of the rare condition points out a problem with this:

“When they heard hoofbeats, the insisted I was a horse. Then they saw the stripes and they insisted I was a zebra. Why can’t they understand I’m a referee who was trampled by jackasses?”