Mystery Solved?

There has emerged a partial solution to the mystery phone call problem.

In the summer, when my friend was visiting, she'd left her mobile phone at work, and needed to call her husband. She used my home phone, but didn't get an answer, so she left a message. So that's how his phone "knows" my number.

But that was more than two months ago. Why it should suddenly spontaneously get called by his recall button after all this time remains unexplained, especially on the eve of our next reunion.