More likely, he experienced derealization or depersonalization. The shake in consciousness can be jarring in that, one realizes the weight of being the "one" behind the sensors, heuristics, and thinking. The ghost in the machine... Really, there are books written about this. The Wisdom of Insecurity by Allen Watts. Life is intrepid and scary because consciousness is a black box. Anxiety is just a symptom of being shown the unusual, being shaken to a core of meaning that defeats the usual humdrum of assumed knowledge.

https://en.m.wikipedia.org/wiki/Depersonalization