I turned my pavoni on to pre-heat, and sadly had to run outside and ended up getting distracted. 10 minutes later, I returned to the house to hear the tell-tale hiss of the machine and opened it to find that the water line was well below the heating element, although there was still water instead. I can see a lot of crystallization/minerals on the heating elements itself. The element was obviously working when I came down, but I am not sure if its been compromised seeing as so much of it was left exposed by the time I shut it off.

Are there any steps or procedures I should follow after making this blunder?

The element turns on, and it will still come to a boil. I am taking the opportunity to descale the machine since I was overdue anyhow. I am confident I shortened the lifespan of the element, and Im guessing it will be less effective going forward, but I am hoping this doesn't pose a safety risk. I will be checking the bottom of the element as well.

It's curious, though, that the boiler would be almost empty after only 10 minutes. Until recently, I kept my millenium Professional on most of the morning and it didn't lose water. However, lately my pressure stat has been sticking and vast amounts of steam are let out through the pressure release valve. I wonder if the "tell-tale hiss" was the relief valve dumping the over pressure steam?