Marine toxins and nematocysts are odd things indeed. Although it is very stupid of me, I have handled all of my corals and anemones without any kinds of gloves and have never gotten a sting. I have even handled a large galaxea with no consequence.
However, I am not telling you this to encourage you to handle things unprotected. On the contrary, I just wanted demonstrate how the toxins can affect humans in a wide variety of ways. The toxins of what I touch without ill effect could quite possibly cause someone else to go into anaphylactic shock, and vice versa.
Always do your research, and always wear your gloves.
ps- letting a critter fall to the bottom of the tank from the surface of the water is more than likely not going to hurt it at all. Of course there are exceptions, so always read up.