I had 20 of those in pots, 60 mph wind damaged several. The damaged places turned to brown rot then the top fell off.
Keep an eye on yours.
Cut the bad section out, the bottom half of the plant with roots will grow a new top pretty quick. It will usually grow 2 new tops, maybe 3 new tops, sometimes as many as 5 new tops.
Let top cutting air dry 1 week in shade then plant in 50/50 sand/soil mix. Keep it out side in indirect sun light. Rooting powder might help it root. It took mine 2 months to start growing roots. Put your top 6" deep in well drained soil and water it once a week.
Too much sun will make san pedro cactus turn yellow. Soil that does not drain well will cause the cactus to get brown rot.
If you want your plant to multiply super fast lay the whole cactus on its side in 50/50 sand/soil mix. Cover the root end with a pile of soil. The roots will grow down and keep the plant alive. The whole bottom side of the cactus that touches soil will grow roots. The whole top side of the plant will grow 10 or 12 new plants.