Thanks for reading!
It's an interesting anecdote, but from my understanding of the system that simply shouldn't be possible. Your house's interior cell isn't loaded into memory when you are outside in Megaton, so there's no way for the NPC to access your items. I think this fundamental limitation holds true for every version of the engine, from Morrowind to Starfield, but I'd be glad to be proven wrong with concrete evidence.
The one item that stood out to me was: "Todd’s mid-fight dagger acquisition Verdict: Impossible in the final game unless scripted to do so"
I do not disagree with the verdict for the final build of the game but I recall observing something similar in Fallout 3. I had stashed a mini-nuke launcher and ammmo in the Megaton player home. Some sort of conflict transpired (do not remember what exactly, perhaps I provoked an NPC for fun), I witnessed one of the town-folk run into my player home (in its own cell) and come back out with my weapon. It is possible with 1000s of hours in Bethesda games I am just mishmashing memories together but I am pretty sure this is what prompted me to eventually download a player home mod (and eventually learn G.E.C.K. by "remastering" it).