Word or phrase when a person vanishes when you look away

Is there a word or phrase when you think you see a person, look away, then look back and the person is gone?

For example, I thought I saw my friend as I walked into a cafe. I looked at my phone, looked back up and he wasn't there. The table was empty, like there had been no one sitting at it.

I asked a coworker if he knew of a word or phrase and he told of a similar situation; he walked in the front door of his home, saw his roommate in the living room, turned right to walk into the kitchen and his roommate was in the kitchen.

He called this phenomenon "A glitch in the Matrix" or seeing a doppelgänger.

I don't think doppelgänger is the correct term, though.

Is there a better phrase or word to describe these mirages or phantoms we're seeing?

Solution 1:

Glimpse -- Cambridge

(noun) a brief look at someone or something:
He caught a glimpse of her face.

(verb) I glimpsed her walking back from town.

Solution 2:

abscond [ab-skond]/ verb (used without object)

1. to depart in a sudden and secret manner, especially to avoid capture and legal prosecution.

If you think that the person was actually there and left swiftly.