The study in question is Carter O, Mills B, Phan T, Bremner J. Measuring the effect of cigarette plain packaging on transaction times and selection errors in a simulation experiment, Tobacco Control, 21, 572–577, 2012.doi:10.1136/tobaccocontrol-2011-050087.
I expressed doubts that removing the branding would make cigarettes easier to identify, but he had none of it, posting the video below to prove how quick it is to pick out a plain pack from behind a screen:
This of course is not proof of anything, it is a video of a single transaction, without any consideration of how sales environments vary.
Professor Chapman has so much faith in this study that it resolves all the plain packaging dilemmas for him (to my mind serving times are nowhere near the crux about why this is a bad idea). To him this is a 'non-issue'. I asked him why he was bringing the issue up, when the study was over a year old.
After a few minutes I managed to find the response from Dick Puddlecote to the study: BMJ's official attempt to 'prove' that plain packaging makes shop service quicker. But I couldn't share it with Simon since he had blocked my response with the following comment:
EDIT: please see comment below 12 February from second Anonymous commenter: my mistake, seems I was the one got the studies back to front.