Even if the menu bar reliably showed up when touching the top of the screen (which currently isn't the case, see Bug 255341), there should be an easier, more intuitive way of recovering from Full-screen mode.
Best option would probably be an additional entry in the context menu.
Git commit 6a6263ee4c9ea373474bd0be4d41153d32145f31 by Andrea Diamantini.
Committed on 31/07/2013 at 16:25.
Pushed by adjam into branch 'master'.
Add contextual action when in fullscreen to easily exit
M +10 -1 src/webtab/webview.cpp