(Gameplay) Possible Cait bug.
This happened two times throughout the game and those were the only two instances in which it occured. The first time there was an Udyr under red team's tier 2 tower in bot lane and I laid a trap between him and I. After the trap was fully opened, he proceeded to run straight through the trap without setting off the trap at all. The second time I was in I blue team's blue side jungle. I ran from blue to the exit into top lane between blue and wolves. I was running away from a Zed and the same Udyr. I laid a trap at the corner of the entrance and flashed away. The Zed jumped over the trap, but the Udyr once again ran directly over the center of the trap after it was fully opened without being stunned. After I was caught and killed, the jungler on my team even comment on the fact that he ran straight through the trap without setting it off. I don't know for sure if there is a bug with her traps, but I think that it may be something that should at least be looked into as the trap is one of the essential parts of Cait's toolkit.