If JW was partners with DW, why would he not answer that call?
First, I just want to say I am very much on the fence about JW involvement. I just don't know. There's not enough info for me to lean in a certain direction. I do think his involvement would be harder to prove than DW's. As to your question: it could have been a pre-arranged signal. I would also ask, in the case that it may have been a text or VM, why would SS be calling JW (of course under the direction of DW) 1 1/2 hours after the money drop? What more was DW hoping to gain at that point? If he was still trying to extort more money, and text/VM was left, then it would have been a call that needed to be returned by JW ASAP and that would have been made clear in the message, IMO. What would be the purpose of a message from SS that didn't require a response by JW? If he was still alive and trying to save his family, he would have left a message saying to respond back as soon as possible, IMO.
What was happening or being decided in those 90 minutes between the money drop and the 11:54 call? What was happening in the more than one hour after that before the fire was reported? I read in news reports that a lawn crew was there that morning. It was not stated what time they were there. Possibly DW had to wait for them to leave before setting the fire. I also wonder why all the different methods of violence. SS was beaten, stabbed AND strangled. I wonder if more than DW was at the home whether they all agreed to inflict their own form of violence so that they'd all be equally culpable of the murders. A pact of sorts. Just things that run thru my mind.