Diagnosis is often based on behavioral indicators: descriptions of your actions... your own interpretation/reaction to environmental cues, etc.

The "telling" of your stories... or any particular doctor's awarenesses of your different behaviors (e.g. thru direct observation or clinical report, self presentation, etc)... could easily render "alternative" diagnoses.

I think it's quite reasonable that these two diagnoses be considered for a given behavioral profile.

Their behavioral manifestations are NOT, necessarily, so far apart.

The incorrectly-identified-broken-bone analogy is a vast oversimplification of symptom identification/management.