You need to use the Touch id system and not Nth Touch :\ Nth Touch in the manual represents the NUMBER of fingers touching. So the Red puck will only work when the second finger is on the screen.
To get a touchid
--start of touch--
onTouch(any puck)
puck variable touchid = touch.touchid
--move puck--
puck var touchid > -1(keep in mind that touchid starts at 0)
-> puck.xy = touch.XAtforID(puck.touchid)
--release puck--
on any touch end
check for which touch was release and then find the puck
you got the rest.
For any multi touch control. You must use touchid references. Nth Touch is nearly worthless unless you are literally making a game about the sequence order of number of fingers actively on the screen.