Newbie question about photoperiods....

I just acquired a plant from a friend and it looks to me that it has been in the flowering stage for about a month. It was root bound and had been transplanted into another pot and it looks like it'll survive, but the plants photo period has gotten fucked up.

I've searched the forum here and i just cant find an answer so here goes. Once you have your plants into their 12/12 and their photo period is interrupted, is there anything that I can do to get the plant back on track....or is it now a lost cause?

... I would personally keep it in flowering..... if forced to play with the photoperiod I like to make the night longer.
...light can trigger the plant back into a veg state, or bring on hermies. Good luck.