Jefe Bergenstein
Legend
First, an afterlife is irrelevant. Murder is still evil regardless.
Why? Because you say? You're from an entirely different world, and thus have different values. The goalposts would logically change in a D&D world. Instead of one life mattering, it would be the impact of the prime material plane as a whole, since that seems to be the forging ground for the afterlife.
Second, raise dead is not guaranteed. If they can't get to town for 3 months, a 10 day time limit is well gone by the time they get there.
Gentle repose says hi.
The soul also has to be willing and able to return. Something the murderer can't guarantee, so raise dead is also irrelevant to whether the life is valuable and the murder evil.
Well, I would think if your companion is having such a great time hanging out in the afterlife they don't want to come back, it really should be "no hard feelings". Life and death in D&D should be weird from our perspective.