If an exchange is faking their volume data, they shouldn't be trusted. It's simple as that.
It's good that you picked up on that because they might not actually be doing anything to the customers at the moment, but the fact that they are willing to fraudulently produce figures for their own good would suggest to me that they are not to be trusted. Unless Hotbit can come out and rebut your arguments, of course.
But for now, i'd definitely avoid them. Wouldn't come as a surprise if the volumes of other markets on their site are fabricated as well. What was the deal with the user getting his account suspended here, btw?
He said whenever he placed a sell order, it never did fill and on the contrary the price kept dropping and strange as it may sound the prices were now 20k sats lower from what it was on poloniex. He complained about this on Telegram an they banned him lol as their little secret leaked :/