"Man that was a f--- up," a tactical police officer said soon after the assault on the Lindt cafe, an inquest has heard.

The man known as Officer B said he cannot remember saying this to a paramedic.

What Officer B can and cannot remember was the subject of intense questioning by the barrister for the family of killed hostage Katrina Dawson.

Officer B was one of two tactical operators who fired in the gunfight that ended the siege.