This is your imagination. Curatolo did not appear "inebriated"; in order to be reliable a witness is not required to show any particular health condition, capability, intelligence or education. In common life any person has a "right" to speak the way Curatolo speaks without being considered mentally impaired (and btw, even mentally deficient witnesses can testify).
If a theory is advanced about a witness being impaired to the point of being barred from testimony, this is something that should be proven, and the burden is on those who advance the theory. The witness does not need to pass a "smart-looking" test. And a judge does not "take as an argument" an unproven speculation. If an expert exam is requested (like, by the defence) and the witness is examined and ruled unreliable due to mental issues, that would be an argument; on the other hand, your guesses are based on zero evidence.
I didn't say I thought he appeared inebriated.
I was directly challenging your unsupported and illogical contention that a witness presentation can never be used as a gauge of the witness.
I never declared that the witness is required to show anything. I did point out (and as you confirmed inadvertantly) the defence can argue that characteristics of the witness can be used to question their reliability. As another example, the defence can rightfully point out that a witness with a known medical condition cannot possibly have witnessed a crime whilst out jogging if their known medical condition prevents jogging.
In Curotalos case, we have a knowable, self-admitted, and entirely compatible cause for his speech and motor patterns evident in his presentation - profound and long term addiction, with - as an actual addiction clinician pointed out earlier - enough concordant evidence to make a reasonable statement that Curotalo had, or was, still using at least up to a point immediately prior to his known video interview.
If a person known to have been a user of a substance demonstrates symptoms concordant with being a current user of a substance, that's not 'zero evidence', it's called 'observational evidence' - you know like Knox's supposed 'la Mossa' and lack of emotional effect is also observational evidence.
Oh wait, I get it now - you only want to dismiss observational evidence when you disagree with the conclusions, otherwise you're just fine with it.