Yes, that's right Good Egg. That was the approach that resulted from the T5 public inquiry, with planning permission being granted subject to a whole host of conditions including those relating to surface access. BAA/HAL therefore had to stump up before it could go ahead with the project.
For R3 the difficulty will be in distinguishing between those surface access projects that are driven by Heathrow's expansion and the (longer) list of projects that are put forward by bodies such as TFL which have an ulterior motive.
TFL's intervention, and Boris's refusal of the LCY expansion, point to the inevitability that Davies will not have the last word. Politics will continue to drive things, and may well result in a repeat of the various historic Govt decisions to expand other airports instead. History tells us that Govt was wrong on Stansted (whose development was made possible by Heathrow's profits), and it could well end up being wrong again by eventually deciding that Gatwick is the least bad solution from a political perspective, even if it makes no sense from an industry perspective.