As far as I understand US and Internation Copyright law the interface cannot be copywritten so it would be permissable to look at the documentation
when learning how to implement the function and then closing your browser and writting the documentation from memory. At least thats how it was explained to me at the first wineconf. Its a stretch I know but there is nothing legally that I can tell that prevents the developer from reading the API documentation and later writting his own documentation. IANAL so take that with a grain of salt. Perhaps the standard should be that the same developer that writes the API cannot document it. Julliards point of view seems to be when you write the interface your free to look at MSDN however don't write the API docs at the same time. Go back later, look at what you have done and base your documentation on your own work.