Hi,
Beyond what AV mentions to get your plant to recover, I can only offer some general plant information, a guideline we used to follow years ago...
When a plant gets leaves that dry/brown at tips, then it is too dry (or the lights too close burning the tips)...
When it browns at the leaf base, it may be too wet, rotting from the base.
Sometimes there are other reasons, like a change in conditions, too warm or too cool a draft, etc.
In this case to determine the cause & not have it occur again, I would check to see that the media is draining well, and not sitting in water too much. Do you have decent ventilation? Also, if you filled the pitchers, did you put anything in them (bugs/fertilizers/etc.) ?
That could cause pitcher browning if it is, as the ferts/bugs are sometimes too big a meal for the plant. On Sarrs & some of my Neps, this occurs when feeding is done... especially when my Sarr pitchers fill with bugs or I over-did the "juice" to one of my Neps.
(Did you "feed" the plant
? Over-doing bugs & chemicals is more common than under-doing!)
Keep a close eye on other leaves... if it continues then you ought to consider changing its conditions (watering, light, air circulation, temps, etc.), but if it is only this one leaf, then perhaps you have nothing to worry about.
Well, that's my opinion on things in short. Indeed, AV has nailed things on the head. He has more knowledge & experience with these particular plants than I do & is advice is as accurate as you can get.
Good luck!
Paul