I would contact tricare and give them the entire backstory of events that happened…then would let them know of all the medical bills that have accumulated thus far and ask what their timeline is on reimbursement for services rendered already…then I would ask them about ongoing care for his dementia in a care facility in Thailand and how or if they will pay for it.
I would even Mention the plane ride over any all extras you had to pay for from medicine to medical Help on the journey etc to see how I could maximize the entire claim.
Because my Philosophy is this…never tell yourself NO let them tell you NO…then you ask what do I have to do to get you to say YES.. but that is me