"Man In The Middle (MITM)" is the important bit. For example by sniffing the wireless traffic on an unencrypted wlan you can capture entire emails being sent or received, without ever compromising the account.
- Request password reset.
- Sniff email with reset link.
- Go to reset link before user does and change password.Still, one time use password reset links with explicit instructions and set expectations to reset the password immediately is the way to go if you're emailing anything IMO.