Ok, I've finished watching the demo. The warden NEVER said that the reds had to wait for his OK to start dodgeball. As such, the first round, all the blues started triggering the traps and the warden never freaked out and neither did the reds. The second round, it was the exact same circumstances, but matsi triggered the traps when the reds weren't really expecting it. He also triggered them efficiently, which killed all the reds. Due to these 2 events happening simultaneously, many people freaked out because it caught them off guard, and they claimed it was freekill because "the warden didn't say go yet." However, unless the warden clarifies he must say go first, which he DIDN'T, its fine to start triggering the traps whenever. +1 for unban. Matsi didn't freekill.
Just as a side note, this is something I always stress as warden. Sometimes I will tell the reds to go to obby and they wont start because I didn't say to start yet. My response to this is always that unless the warden clarifies when to start, you are allowed to begin once you reach there.