I have a question r/skyrim...

I will try to keep this as spoiler free as possible.... So, I was on my way to [killing the first lady from Nazir (i believe) for the dark brotherhood, she's in Dawnstar] (/d) and when i was sneaking outside this random guy sneaks toward me and gives me this really nice [Dwarven armor with an enchant on it to help out heavy armor stat] (/item) and he said he'll be back for it and if I snitch then he'll kill me. It's been approximately 3 irl days and a lot of in game days and he still hasn't returned. Has this happened with anyone else, and if so what happened/what did you do?