These contestants only had Gavin and Grey in mind. All of them firmly believed that those two had struck it rich and had run away with the treasures they found, so they were naturally anxious to catch up to the traitors. They had no attention to spare to their surroundings at all.
So Sheyan let them pass without stopping them. After walking for about five or six more minutes, he climbed up a high ground to survey the surroundings. By this time, Sheyan was already pretty confident in his deduction.
"The principle behind the Wraith's stealth function isn't very complicated. The Wraith needs to store electrical power so as to continuously supply energy to the light refraction device on it. That's why after being in stealth mode for a certain period of time, the Wraith must deactivate stealth mode to store energy again. Now that the Protoss have achieved complete victory, those people wouldn't dare to fly around in a Wraith that can't turn invisible... "
