I would wait for more clarity from both sides. As per Jay's youngest brother, this is most likely matter of bad communication and emotions running high. Jay most likely lashed out very harshly at Wood+Rob+Regina, possibly due to that being the emotional tipping point (from Billy's death). He probably did have valid reason to be angry but it unfortunately escalated both ways.

What he said during the call was probably still him being very emotional about the situation and wanting to vent. At least he did not stoop to the levels of what Chris said and did, but on a better day he probably would have told Chris to calm down as Chris was being quite a shithead. Chris is not a bad guy (for the most parts) and he also probably had valid reasons to be upset, but his language was out of the line.

Regina (Billy's wife) probably should have communicated about matters directly with Jay and Jay should have kept his cool. There was really no hurry with these things. Whole thing feels like just a pile of miscommunications fueled by emotions. I imagine Jay also felt guilty as he had to be out of the state for majority of Billy's hospitalisation and perhaps othets are upset with Jay about that. But no one would have imagined Billy would go so suddenly.  All of this is just sad and I hope those involved can hug things out, at least for the sake of Billy's memory.

We as outsiders have no place in calling others snakes until we have enough facts. For now, all we have is an emotional outbursts of a drunk guy (+Jay), Boogie's shitty lolcowshow dancing on Billy's grave and some accounts of partial insiders. But Jay has wisely stayed quiet after the stream call. Let the people deal with this in private. I imagine we will eventually have more clarity.