The key that is punched into the input field is based on where your finger lifted up. So if you have slide-to-type on, the pop-up paddle that showed up on key-down won't change to where your finger slid to for key-up. That's why when typing fast with slide-to-type on you can get confusing UI hints like this.

It kind of seems like the grace period for the paddle hiding with slide-to-type needs adjustment. I just leave slide-to-type off.