The worst thing about all their dodgy behaviour lately is when a coin peaks and no-one can trade (or close open positions) how does the coin value dive so severely while the site is still inactive? seems too suss to me.. and to make things worse you cant get any responses from support for the last week or two.
Although I am also really annoyed whenever that event happened, I can understand the value diving as the influence of other exchanger. As you, I believe, understand well, the price of one coin at bittrex can affect the price of said coin at polo. So, I figure that the price plummeting was because they dumped the coin hard on bittrex as the effect of polo's server breakdown.