I've been following that looping waterslide for some time now and they did incorperate a bunch of safety features into the final design. One is the tube is somewhat translucent, so the lifeguard on the tower can physically see the shadow of people passing though the loop, or getting stuck, whichever the case may be. Another is there is a hatch on the top of the tube just before and after the loop, so if someone does valley they can let themselves out, and there is a walkway outside the tube. Also inside the tube there are arrows and words in a few different languages directing people to the nearest hatch if they do get stuck somewhere in there.
It's pretty neat actually.
Favorite Wood Coasters: The Voyage, Ravine Flyer II, Thunderhead, Balder Favorite Steel: Voltron Nevera, Steel Vengeance, Expedition GeForce, Olympia Looping Parks visited: 232, Coasters Ridden: Steel: 894, Wood: 179, Total: 1073