I am back and read all the posts in the thread..
Thank you all for your input and I apologize to you Mike if there was a miss understanding by Cyber.
Regarding the insurance, we are in Dubai and and it is confirmed that only the warranty can fix it for free but unfortunately it is expired (1 year) also there isn't credit card insurance nor a law like in Europe.
I know this friend and honestly, he takes care of his cameras way more than I do. Like when we are out for shooting I don't mind changing the lens, he doesn't. I travel with normal bags, he has the mafia movie like protected silver bags with foam cut to fit the camera equipment to transport. Also he mostly do underwater photography once or twice a month only. So I don't think there was a miss use, also Canon repair center said via phone that there wasn't miss use nor electric mass to remove the water leaking probability.
Also, I think when I first posted the thread both of us were more emotional. As mentioned things happen. It is disappointing for such a pro level camera but still it can happen. He is convinced to pay and fix it, but he wants to sell it and get a new one. Which I told him that i am against because it will be fixed and he will only make his loss bigger plus the same thing can happen again. He is stuck with the 5dm3 because the housing of underwater photography is more expensive than all the lenses and cameras he has and it is hard to sell.
Regarding my concern about my camera, I had a great experience with the 5dm2. I bought it used and used it a lot almost abused. Like very high shutter and it fell many times and been to the beach, desert, snow and alot of travel and thankfully nothing happened and I sold at almost the price i bought it for after 3 years. When I remember that I feel better and more confident that the mark 3 will serve me a lot also.
Cyber, it is really good for you that they accepted to replace your 1dm3, which is even more expensive than the 5dm3