Strange Google+ sharing behavior

I only add people to my circles who already are on Google+. You can surely understand my surprise when while being about to share a link I was presented the option

☑ Also email 1 person not yet using Google+

1 person not yet using Google+

I beg your pardon? The person in question is not in my mail address book and supposedly is not yet using Google+ so one has to ask what has happened.

My first hypothesis was that Google messed up th message and that the option in fact should read

☑ Also email 1 person currently not using Google+

The obvious next step is verifying someone originally using Google+ has stopped doing so. Said, done.

Elvis has left the buidling

Initial hypothesis turned out to be right. I guess a tactical facepalm is appropriate.