dvo - no way of telling for sure who has voted for what, but people generally leave a comment with a rating at the moment. So if a sub has got 5* and no comments there's a reasonable chance that the writer has awarded those stars. Especially if they appeared within 12 seconds of the sub being posted.
Everybody likes to get stars, and, in defence of anybody that does it, the text at the top of the writers' room does actually include the line "so if you would like to write for NewsBiscuit please post your article on this submission board and then attempt to give yourself maximum votes over and over again", so people are only following orders.
Giving everything you sub 5* does tend to wind some people up on here though, as I discovered quite early on. So I stopped doing it. Honest, I did...