Guess that's what you'd call "having expectations"?
I'm not sure I can blame Mayaka. I would not have thought of anything when I saw the handkerchief, and I would have been stumped (but defaulted to no action) if I saw a wallet with nothing in it. It would have taken one more item for me to get off my butt to finally check out what was going on, but Fukube arrived by that time.