I think that clinches it for me. Its best to get these straight in your head before they actually happen; if it happened when you were TJ / ARing you would need an instant decision as you just wouldn't have the time to think about it. So
- If the ball had crossed the plane of touch and gets knocked on - its in touch
- If the ball had not crossed the plane of touch and gets knocked on - its a scrum
And on a slightly different note, a player kicks and chases the ball which is bouncing/rolling in the FoP parallel to the right side (for this example) touch line and with his right foot in touch, kicks the ball again with his left foot (remember the ball is still bouncing/rolling along in the FoP) and is able to play on. Correct?