I've heard this as a theory that's been suggested, but not sure if it was raised by the police.
In any case, it doesn't make sense to me. It comes from the fact that JC got Shirley Banks, the victim he abducted and murdered, to call into her work the morning after he took her to say she was not coming in as she was sick. So it was suggested maybe JC did this with SJL and got her to call into the pub. But the two cases would not be remotely comparable in my view.
First, it made some logical sense for JC to get SB to call in sick as it would stop her office from raising the alarm if they noticed she was missing, called her house, the police would have been called that morning. What would having SJL pretend to be a different person calling the pub looking for SJL do? If JC wanted to stop SJL's workplace raising the alarm she was missing he'd just have got SJL to call Sturgis and say she had been taken ill and was going home to rest. Calling the pub looking for herself does nothing to put anyone off the scent that SJL was missing. The pub would not care less whether SJL came on time, or not, she was not an employee, she was someone who would pop round at some point to grab some items. Also JC forcing SJL to call the pub and say what CV claims was said just raises suspicion if anything.
It's one thing for JC to force SB to call her employer and just say hi i'm unwell today, and another thing entirely for him to force SJL to call a pub, to talk to someone she doesn't know--anyone of the staff could have answered--and pretend to be a totally different person, have a detailed conversation about keeping SJL there, which sounds bizarre, with that stranger, give a phone number, etc. I can't see how you could force someone to do that, realistically. It's a hypothesis that makes no sense, has no purpose. And JC would have known she worked for Sturgis if he were Mr Kipper, and even if he wasn't and just happened to bump into her and abduct her, she was carrying a Sturgis key fob with her car keys on it (even if she wasn't holding the house keys). Why not get her to call her office if he wanted to force her to phone someone? How did JC get hold of the pub phone number? He got the info out of SJL about where she was going, and nipped to get a phone book? Called directory enquiries (which could incriminate him if the calls were traced?)
The most likely scenarios for those phone calls are:
1. CV made them up as discussed
2. CV got some calls but they didn't happen when he recalled them happening, but were people looking for SJL later that evening, when the police did get involved, and they did know she was supposed to go to collect her stuff because two officers went around to the PoW on the Tuesday morning to get the stuff from CV. And CV recalls in his chat to DV that he was surprised things happened so fast (I bet he was...)