If he was a nut job, the elders likely knew he was a nut job and didn’t refer him to proper help, instead it seems they excommunicated and shunned him likely exacerbating the issue. Given the time and descriptions it sounds like he was there perhaps on a judicial committee or review to reinstate and wasn’t happy with the outcome?
Not sure about the wife, seems she was either an accomplice or a victim, depending on who you ask, but it seems this was premeditated and the wife didn’t warn anyone that her husband was making a bomb at home, making her at least an accomplice to that part of it.
The WTBTS also made sure to refer to them as ex-JWs meaning they want to officially distance themselves from them for some reason, great compassion there.