Genetics definitely play a big role. General rule of thumb, the later the strain finishes, the more tolerant it will be of transition, the earlier it finishes the easier it will trigger early. When they do flower early, sometimes they go back into veg, sometimes they don't. Really depends on the plant, I've seen it go both ways. I have had some plants snap out of it fairly quickly and continue to veg and I have had others that never went back into veg and just sort of stalled out for the rest of the season. Even if they re-veg, you lose a lot of precious veg time which hurts yield. I have also noticed the plants that have flower issues, even if they re-veg, will tend to flower earlier in the season than they should, and will tend to put out less developed, more airy buds.