I don't agree personally, but it is 100% legit because they were in a party UNLESS the person that died (the base owner) told his party member after he died, then the base owner broke NLR.
Quote from Neko
Like, the whole reason you need to get involved first before killing someone who is killing X person is to make it so it's NOT low effort RP.
If you aren't involved in any way to the person, NOW you need to talk it out first. Being in a party ALREADY makes you involved with the person. Hence the reason people make parties!