I am sorry but you should provide picture of the whole plant and the problem area in natural light. With pink/purple light I bet it would be hard to give a proper diagnosis. However, since this plant is at week 12, she is almost finished with her generative period, we can observe pistils going brown also. At this stage the plant may show all kinds of anomalies regardless as it is prioritizing everything to the buds. I'd say rest easy and continue still for couple weeks and about then it should be the harvest time.
I stress this that it is completely normal for auto to start showing all kinds of spots on its leaves at the very end of the generative period.
...:smoking: ... pistils got cooked by something, they are pretty fragile structures (they catch the pollen),... water, intense exposure,.. most likelt things to cause this on tops where newest ones are emerging,.. nothing to sweat here really!
I agree with the masses here really, there isnt much wrong with that one at all. I think that we all get burnt tips, i know that i do.
I will say that the pistils show that she still has some time to ride, i dont see them receding yet so they intend to bulk up some.
Like @Waira said the pistils are fragile, i have damaged them just from the oil in my fingers and repetitive touching mainly when i pollinate the plant by hand.
Now thats a whole other reason to watch pistils brown.