Octet has asked me to comment about whether it be deemed a write off.
This is my personal opinion from 25+ years in the business!
Firstly, hopefully, AKVai has paid for Legal Protection at renewal. They can fight on AKVai's behalf about any issues and when I used to work in the office, we always let the Legal team sort it out, which invariably they did.
As far as the third party insurers deeming the car a write off, then both insurers tend to communicate together to look at the best way of moving forward whilst keeping AKVai happy!
Personally if AKVai is not happy about write off, then they could always get an independent engineer to make a judgement.
I would recommend AKVai contacts their insurers and their legal department ASAP to speak about this.