1

Keep your finger/thumb on the screen for the whole of this...

Gently scroll down to begin the toolbar collapse, but don't let it fully close, then gently start scrolling up, you can see that the toolbar's state doesn't fully revert, even allowing a pull-to-refresh:

Safari handles this effectively and it's impossible to catch it between states:

1.3.19 (2) (WebKit 8620.2.4.10.7)

18

    No one is typing