It is frustratingly unclear how many calls there were between SJL and the PoW. The sequence appears to be that the PoW called the bank called SJL called the PoW. Some accounts say there was a second call; this can only have been to change the time of the pickup. If the original arrangement was at 6pm or thereafter, and the later viewing derailed this, all she'd have needed to do would be turn up at 7pm instead, as
Cherwell points out. So any second call must have been to propose a material change.
The reason you might call ahead is to make sure the person you just spoke to about your lost property will be there at the new time you're about to suggest. Nobody was going to clock on for work at 6pm, but be gone by 7pm leaving SJL to be met by nobody who knew about any lost property. That makes no sense. If you were going to be there at 6 but you showed at 7 it's no big deal because the same pub staff would all there anyway. SJL just turns up and says Hi, sorry, running behind because something came up.
This leads you to think that, if there was a second call, it was for SJL to organise a substantially different time to 6pm; like, right now. She'd check to make sure there was anyone there right then. There'd be no need for such a call otherwise.
I infer DV thinks this amounts to a hole in CV's story. CV said she was going to come over "later". The pub would be closed from 2 to 6pm, and the diary says she had to be elsewhere at 6. Her mother's 30/7/86 interview suggests she was playing tennis afterwards (we don't know where or with whom). This doesn't leave very much of "later" for her to fetch the diary. So did she really make that 6pm arrangement? If she did, she would certainly have had to change it when the 6pm viewing request comes in, clearly to "right now", because this wipes put her free-ish slot that evening.
So why was CV silent on this? Did his story change because he realised a year later that saying she was expected "later" no longer worked when her other intended movements were known? Did she need the diary back fast because it contained numbers she needed to call that afternoon?
Overthinking this is as bad as underthinking it. The alternative narrative is that CV just misremembered what had happened, there was no tennis because SJL edited her life heavily for her mother's consumption, there was no second phone call, etc.
But it still leaves a nagging doubt. If there's no significance to the PoW visit why does it look like CV's story changed, why did AL's story change, and how did property possibly lost somewhere else entirely on the Friday come to be found only two days later at the PoW?