The actual sprayer nozzle sits towards the back of the bowl and sprays up at an angle so any dripping is going straight down into the bowl not landing on the sprayer nozzle.

It's getting fresh water, not recycling bowl water, I suppose there could be some small risk if Larry has explosive diarrhea all over the nozzle, but its probably no worse than if you have any splashback after using a regular toilet after him. Most of the models I have used also have a self-cleaning feature that will have the nozzle rinse itself (they still do need to be actually cleaned periodically of course)

There is a little bit of splashing, unless you're abnormally small and skinny though most of it is probably just going to get your butt and staying in the toilet, once in a while I'll get a couple drops on the front of the toilet seat and I'm pretty sure that's just over-spray shooting directly between my legs, not poop water splashing off of my ass