Few questions. Have these plants been in the same container their entire life cycle? What type of soil is that? What are your watering habits, how often/much? Do you have a way to monitor pH?

How long did the plants go back into veg for?

Don't worry about brown "hairs". The average life span for a pistil is only around 30 days. I usually start to see dead pistils from day 30 through harvest, but it has absolutely nothing to do with ripeness of MJ. Pay attention to the trichromes that form on the leaves and buds. They will start clear, then go milky white, and finally as they begin to degrade, they will go amber from oxidizing. When you harvest is up to you. I typically harvest when trichs are all cloudy white with just a speckle of amber. There are as many opinions on this as there are growers, it'll take time and multiple harvests before you know your preference.