Seems like a ridiculous way to decide who translates it. Why don't they just pay to have it professionally translated by someone reliable?
Although our esteemed colleague above is correct I'm sure in many cases, I simplified (what little I know of) the process - from what I've seen applicants offer or are asked to show previous works and feedback, so it's not just using google translate, at least for any ICO who wants to be taken seriously (and they are few and far between!).