he repeatedly used technicalities and weaseley language to refuse to admit it

see

Yet, Mosseri repeatedly said he was not an expert in addiction in response to Lanier’s questioning.

Even if a nonexpert claims something is clinical addiction, they’re a nonexpert & their word is meaningless. For a credible statement, they’ll need to admit relevant evidence instead of ask a nonexpert.

Imagine being asked for a medical diagnosis when you’re not a qualified physician. It’s perfectly fair to point out you’re not an expert on the matter & point out your awareness of distinctions between imprecise conventional language & precise, scientific definitions.

No one is obligated to volunteer dubious claims to antagonize themselves on the stand just because you want them to.