only the first one is legit ERB of course. I guess there isn't a test in the test suite for multi-page results, otherwise it might have been caught. Someone else reported this same thing like a week or so ago.
JPW•
I was confused, googles it, found a page that suggested erb might actually work on one or both of those odd cases, so if thats true a test case would pass.
However the real issue is whatever generator code they use for adding pagy() is inconsistently handling something.