Hey Legacyvet:
I'd like to join Mutt, Skip and JRHarvey in welcoming you.
I'm so sorry about the fight you had. It can be very upsetting. My situation is a bit different, but I've been very upset from my sister's rage events. Growing up, my dad was extremely critical and he would get angry about how a kitchen counter top was cleaned (sponge marks), blame a family member for a nick or scratch on something. You might find it interesting to read a post on this same board from a couple of days ago. The title is "I cooked too much broccoli". Many of us can relate to how minor issues can turn into a very unpleasant situation.
Has you wife ever been in therapy or treated for any mental illness before (any meds prescribed by a primary care doctor) ?
There are a lot of helpful people here and a lot of good lessons about techniques to use for interacting with disordered people. It can seem overwhelming right now, but you might find that gaining certain intercommunication skills can be helpful. If you look to the right of the page, you will see some links to various lessions.
A Theory of the Pattern of BlameYou might find the article below of interest.
https://bpdfamily.com/message_board/index.php?topic=271911.0.