When adding chemicals to the tank you should always add them to an area of high flow to disperse them quickly. The anemone probably got a taste of some highly concentrated water and reacted by withdrawing. It should be fine and be back to normal in a day or two.
As for the tips, they look fine in that photo. From fishlore.com....
"There is much debate and speculation as to why these tips form. Some think that very high lighting levels are required or even that more actinics are required in the lighting scheme and other hobbyists feel that frequent and varied feedings are required. Whatever the reasoning for these bulbs forming, for long term success with this anemone you'll need to provide high output lighting such as VHO
or Metal Halides"