If by down channel you mean dom down traverse>>non-dom up traverse>>dom down traverse, than the answer is: it doesn't matter whether RTL is broken on decr or incr volume. Your sequences for second dom traverse is completed and we are done moving down. If the sequence for 2nd second dom traverse is not completed - you don't have the channel yet formed and you have to fan regardless whether RTL is broken on decr or incr volume.
However if you meant traverse when you said channel then the answer would depend on whether or not it's a ff traverse of 5 min es level. Post a chart.
