I can't speak to Dolphin, but many (most?) CAM programs simulate off the internal data structures that drive the post processor.
Because of this, they may not show you what your machine is actually going to do, either because your post is wrong for your machine, or because there is a bug that affects the internal data structures that the simulator doesn't see.
For that reason, a lot of machinists like to use a separate simulator to see what the g-code really looks like. Most g-code editors have a simulator built in, for example.
Of course your machine controller will also show you what it looks like in most cases too, and that's really the horse's mouth, though the machine may not be sitting next to your CAM program.