I once had a slot freeze, and I gotta say, I got super stressed. It froze right in the middle of a spin. After refreshing the page, everything went back to normal. At that moment I was playing on slotsvadergames.com, later wrote to support to check if everything was fine. From what I remember, I found out that in proper casinos everything is tracked on the server, including results. So money doesn’t disappear, even though the situation is pretty unpleasant.