If I proposed my PhD this year (but have not defended) can I say that I graduated this year?
No, you can't state that 2015 is your graduation year. The year you graduate has a well-defined meaning -- it's the year the university confers your degree to you. Period. Writing that 2015 is your graduation year would be the same, ethically, as writing that 2013 is your graduation year just to make your resume look more impressive.
Your resume will, correctly, indicate that you're working at the same time as completing your degree, which should be impressive enough for anyone doing bookkeeping on your dates.