People taking ketamine in clubs usually use much less than k-hole or anaesthetic doses, because the effects are more conducive to partying. They generally take small bumps over the course of a night.

I really doubt the club kids to saw had taken anything like the equivelant of 300mg or 500mg taken IM (2x the bioavailability of intranasal), or even intranasally. If you are standing, 50-75mg taken intranasally can cause transient, trance-like states like you describe. 100mg taken intranasally (50g IM equivalent) is enough such that most people couldn't safely walk, and would have closed-eye visuals almost like a lucid dream. 150mg intranasally will guarantee a k-hole for most people, and 300mg plus would render all but those with extreme tolerances unconscious.