Yes, lock, stock and barrel. Absolutely guilty. IMO there were several contributing factors that coalesced into a perfect storm. The very heart of it all was Chase's gambling addiction and a lifetime of thievery and cutting corners. Chase saw a window (no pun intended) of opportunity with the QB and what he could skim off. Once Joseph saw the check cleared the bank he called the bank, twice. Then he called Chase.
Between this and the missing check(s) to MSM that Joseph now knew about infuriated him enough to put an end the the relationship, friend-wise and business-wise. Something else to add to the interview with LE, when Chase said his business was "done" he sounded pretty damn confident that he knew it to be the case. I now don't believe Joseph not only met for lunch (or whatever) to severe ties with Merritt, but to confront him and get his money back from the check that Chase cashed.
On the last call with Chase (5:48), Chase's phone either dies or is turned off a minute or less after, yet according to records Joseph's phone is still on the call for 2 more minutes. This means he was talking to dead air. Whatever Joseph said to Chase, this was the defining moment that set the next chain of events in to motion. I'm almost certain that Joseph said Summer's name, and probably more than once. It would send Merritt into a blind rage. It wasn't that Chase was out of a job now. It wasn't that Chase lost out on the opportunity to be dipping into millions of dollars that EIP would be bringing in over the next few years. Chase's rage and murderous motivation was over Summer Mcstay and that Joseph was "P***y whipped". Summer was the catalyst and he was determined on absolutely destroying her, as she, in his mind, destroyed and took away his livelihood. This is evident in the overkill she endured.
I have not a single doubt in my mind of this man's guilt. Aside from what we have seen of the overwhelming evidence, I have personally talked with a multitude of people who have been involved with this man on a close and consistent basis over years and even decades, who say he is absolutely capable of doing this.
Whatever the case of what happened at the meeting, we'll probably never know for sure but I do believe Joseph made it home. In his interview with detectives Chase made a major foul and stated the last time he talked to Joseph, he was at his desk. There is no way I believe that this was in a phone call, as Chase professes. He was standing over him.