1:1 upload does not mean the whole file was uploaded, only 'that number of bytes' were uploaded.
BitTorrent uploads by picking blocks at random. Consider this: how many rolls of a 6-sided die do you need until all 6 sides are expected to show up? In the general case, something like N log N.
So for a 700 piece file, uploading ratio of 2.8 to 1 is more like it and even then, that is only the expected value.