Happens often with some clones and a lot of re-veggers. Normal growth returns about two weeks after stress has been relieved.

Personally, after a root trim (bonsai or re-veg) or cloning, I keep the ladies under 18/6 (maximum) till the roots heal, and resume normal growth. But then again...I veg under 18/6 with the belief that the roots work more during darkness, and the foliage works during lights-on. Possibly an old wives tale, but nothing relevant I've seen on the subject tells me otherwise.

Early trichs...? Have there been any changes in your lighting spectrums or schedules? Could just be a stress-induced event...but I'd watch for what kind of pre-flowers you start seeing. (calyx's or nanners)