A tetsubin problem- help?

Heya,

So I recently received a kotobuki tetsubin, only a couple years old, from a friend. She got the tetsubin from a yard sale, and where it is in very good shape, some of the paint on the inside of the spout is chipping. A couple questions.

What’s wrong with it? Was it washed incorrectly?

Also,
Although I rigorously brushed off the ripping paint, is it safe to drink from?

Thanks!
-Jesse