My guild is currently working on Heroic Lei Shen. I was told that if we do not kill it on heroic, we can have someone sit out and kill it on normal saving the lockout. We can then extend with the person that sat's lockout and be able to start from Heroic Lei Shen next week. This true? I just wanted to confirm with more than one person lol.
As long as one toon (I'd make it 2 people just in case stuff happens) has not killed Lei Shen this week, you'll be able continue at H Lei Shen next week.