As whitewater paddler on the alps you get used to relying on the weather report (and develop a healthy judgement for what's the kind of rain that will get you in trouble). The kind of rain it takes to make trouble doesn't come out of the blue :)
Still, the cave has rescue spots that are fully equipped with food and thermal blankets and have several meters height as buffer. And still after all of that you are right, it always is a risk
Does the water have any kind of smell to it, or does it leave a smell on your skin after wading through it? Probably ultrapure from filtering through the rocks, I'd imagine, although there are microorganisms that live in some caves so maybe not?
The limestone above is not high enough to really filter out whatever the farmer on top throws on their field, so it's contaminated with pestizides and not recommended for drinking. It smells like fresh water.