It's a clip from one of the documentaries that are linked earlier in the thread. He says they went to have a drink in the pub next door (to Mossops) and that is where she lost or had her items stolen.
As noted elsewhere I am not a fan of DV's interview style and I don't really think he gives full context for his interview reporting. So AL's remarks to him in the interview he had -- before AL stormed out-- don't have much context other than what DV gives us, and he is trying to portray this as "weird". We have no idea what AL thought the interview would be about, what line of questioning DV was going to take, if he knew up ahead there would be two people interviewing him (which alters the balance of power), or what the interview was going to be for e.g. was it going to be a splash in the Sun or Mail?
AL might have thought DV was being aggressive or intrusive or hinting at accusing him so he got annoyed, shut down, said nothing happened, and just left.
Incidentally in this extract you can see how DV is setting up the theft of SJL's stuff to be a big deal with words like "oddly absent".
Here's the quote from DV's book for the benefit of those who have not read it. The context is that DV and his assistant have arranged to meet AL in a coffee shop in London to interview him. By the time this section below happens, the interview is not going well. DV is asking him a lot of questions about his movements in the last days before SJL disappeared and his interactions with her. It comes across like DV is being quite aggressive with the questioning--he is asking a lot of questions as if this is a police interview. It's not a chat. So by the time we get here, AL is described by DV as "tense". The last question prior to this is "did you ever read anything about SJL that upset you?".
AL then storms off. My feeling is that the rather aggressive and personal questioning right from the get go, two people he'd never met, unclear reason for interview and probing questions, just p**** him off and upset him. It's a weird dynamic, there is a power inbalance here, AL is almost put in the position of a suspect, it might have brought back unpleasant and stressful memories of his extensive questioning after SJL disappeared which cannot have been pleasant.