They took custody of the body after killing him so they'll have made sure it was definitely him!! But they afforded him a Muslim funeral which, to my knowledge, has to happen within a small time span of death!
I don't see why so many people (and I've heard it from quite a few!) have a problem with him having been disposed of at sea - or so quickly!! He's dead!! That's all that matters!! Now the world just needs to brace itself for the retaliation!!