A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from a copy of the forum saved in October 2015, so pages it didn't save are missing. Players' names are left out; the rules officials are named. Rulings are as they stood on these dates; later rulings, the rulebooks and the Rules Archive may differ.
In reference to this unanswered question: viewtopic.php?f=59&t=100598&p=1325552&hilit=The+Law%27s+Strength#p1325552
My friend was at Feeding Hills, MA Kotei over the weekend and said that it was judged that the active player may choose to play Know No Fear to negate the movement from The Law's Strength, leaving the stronghold effect from Twin Forks City around the victor of a duel. Is this the case?
[Fixed]Know no Fear creates an ongoing negation effect with a priority of A. Twin Forks City will then try to kick in with also a priority of A. Since both have the same priority, the active player gets to choose which one kicks in first. If the active player chooses to apply Know no Fear, then Twin Forks City will try to kick in again when the conditional destruction effect from The Law's Strength tries to apply.[Fixed]
Based on this recent ruling: viewtopic.php?f=59&t=102270&p=1345106&hilit=Twin+Forks+City#p1345106
I thought TFC would trigger at the same time if not before the opportunity to play Know No Fear since it is a trait. Thus The Law's Strength still kills you and you wasted Know No Fear.... I hope I'm wrong though.
I have fixed the other ruling, but not for the reasons you state. Even though Know no Fear is a reaction, it is played after targeting, which comes before the movement effect tries to apply. Therefore the timing conflict isn't between a reaction and a trait, but between an ongoing negation effect (originated by a reaction that was played and fully resolved) and a triggered negation effect. Therefore sometimes you'll be right (if the active player is the opponent) but when the Crane player is active he gets to choose.