The arming time of hunter traps is currently bugged. As of patch 3.0.2 traps were meant to arm after 1 second. This is however not the case on WoTLk classic. All traps arm randomly between 1 second to 2.61 seconds which is absolutely game breaking in arenas. This behavior is not consistent at all.
It is very easy to reproduce this bug, there are no wild conditions or anything like that.
This github page has full details on the bug:
It does even have the screenshot referencing patch 3.0.2, which you can also check here:
As I said - this bug is absolutely gamebreaking for hunters in arena. Utilizing traps especially freezing traps is a core part of your gameplay. The delay makes it so that more often or not holy paladins can simply walk out of a perfectly timed scatter trap before it even arms due to their disorient reduction. However in the worst cases of luck I have had discipline priests able to shadow word death my freezing trap off of scatter due to max delay times on a freezing arrow (travel time on freezing arrow gives enough time if you’re unlucky enough). Since the times are random this also removes high skilled plays such as freezing trapping off of cyclone which needs you to understand the timings of traps to the fullest - the randomness prevents this.