He owned a little one man auto body shop & was our living for years but got to the point where he couldn't work so our only son took over & my husband got so violent he went & dumped all the paint & thinners on floor & wanted a match to set fire to shop & rammed his pickup into shop door with my son nearly getting hit! My question could this anger have been because he knew he was sick & could no longer do what he loved to do?? He was forever busy & loved his work!!!
Read the forum under dementia and you will see so many instances of sudden and unreasonable anger. Google the different types of dementia and how they manifest.
I think there is a good chance you are correct in thinking this could have had something to do with it if your husband was otherwise not violent and if he had no history of mental illness.
Did your husband have an autopsy? Was there any sign he might have had a stroke or a bleed or a tumor?
At this point you may never know, but I am thinking your guess is as good a guess as any. If this was behavior not native to him then SOMETHING was up.