coming back from parking lot on the highway

Today I had the classic case that someone in front of me on the motorway (it was very dense traffic, speed only about 50 km/h) did not ‘let’ a car coming from the acceleration strip of an AB rest area. The car coming from the rest area then drove on the stand strip for a while or shunted in front of me. What really applies here? As far as I know this has nothing to do with zippering procedure, but the driver on the acceleration strip must But as in this case, he was not let in and had to drive on the stand for a while. Has anyone here actually committed an offence of order at all?