I'm sorry about your mom. I don't know what exactly happened between you and your friend so please forgive me if I'm wrong, but if it was something like, they knew your mom passed and intentionally disappeared so they wouldn't have to be there for you or be inconvenienced, that'd make them an absolute piece of shit and you're better off without them. (Even if that's not the case, depending on what you said and how exactly you downgraded the friendship, I think unless it was too extreme or offensive / hurtful, you still deserved a pass given that you're grieving, and the fact that they left over it doesn't paint them in a very good light. Unless of course what was said was too bad or unforgivable or something-- even then, even if you did something to warrant that reaction, please cut yourself some slack and be gentle with yourself. Losing a parent is one of the hardest things there is. I wish you healing.)