Many people, when close to death, expect it and have become okay with it. They are going to a better place, free of pain, where they can live eternally in glory. This is basically the definition of the double effect doctrine, and even though it may be sad to see a loved one pass, it needs to be used.
The Doctine of Double effect explains the permissibility of certain actions that result in serious harm, or in certain cases, imminent death. When making end of life decisions, I believe any individual is subject to a vast amount of possibilities in a microsecond, and should therefore be aware of any of mental process that takes place in that situation.