Just one question (big spoilers)

I watched someone play the game on YouTube and also watched all endings just fyi. I'm just a bit confused about one thing. James keep saying Mary died three years ago right, but then why are her body in the backseat of his car? Now I know it's not official shown but in the ending in water he sit in the car and talk to her and he glance back toward the backseat where you can kind of see a blanket covering something. And in another ending stillness mary are in the backseat and talk to him. So back to the body wouldn't he have buried her? And since he haven't wouldn't it smell terrible and be decomposed by now? In the rebirth ending the same blanket are in the boat as he goes to bring her back, if he do that wouldn't she be a rotting zombie? So did James lie about her dying three years ago? Another thing that confuses me is that Laura said she met Mary at the hospital one year ago so has it really only been a year? Can someone explain or is it some sort of James are just crazy bs?