Tested this with the macbook pro touchpad.

With the attached example when doing this

 - Put 1st finger on touchpad without pressing

 - Put 2nd finger on touchpad without pressing

 - Put 3nd finger on touchpad without pressing

 - Press the touchpad with the 3 fingers

you get this output

qml: PRESSED   <-- when putting 2 fingers on touchpad
qml: 0
qml: 1
qml: PRESSED <-- when adding the 3rd finger
qml: 2
qml: PRESSED <-- when pressing with the 3 fingers
qml: 0
qml: RELEASED
qml: 0
qml: CANCELED
qml: 1
qml: 2

For me this goes against the fact that the documentation says that the pressed signal is emitted when "new touch points are added" but in this case the point 0 was already pressed and had not been released or cancelled yet.