Isn't Triangle Kush another name for The White? My cut of The White never did that during veg, only when revegging.
I have only seen that when I had soil that was way too acidic, and at that time I was observing other weird problems as well, really bad lockouts and shit.
You know, I really don't know *why* root bound plants tend to go into flower, I only know that the smaller the container the more likely they are to go into flower, and when put in flower they will finish more quickly. I wish I had a definitive answer on why, but what I do when I see it is I get that girl repotted. If she's in the biggest size pot I can physically handle (3gals for me), then the green material on top gets whacked down hard, then I go at her roots and whack those down hard. I've take away as much as half the root material (sides & bottom) without causing a problem.