Never mind "Reread the government leaflet explaining the decision as a once in a lifetime decision". We are not governed by government leaflets , we are governed by the Acts of Parliament enacted by the government that we elected to do this for us, which is made up of NMPs from all the different parties in the country.
Read instead the actual Act of Parliament, which officially defines the mechanism for holding the referendum, in detail. It does not mention that once the results of the voting have been counted, if there are a majority of yes votes, it will become law, it just sets up that the question will be asked.
If a law were to be passed that defined a dog, and then a leaflet circulated that said that every dog must be painted blue, would you take that to mean that by law every dog must be painted blue? A ridiculous example, but it would be a parallel case. What a leaflet says is information, not law. and information can be mistaken.