Neighbor Insists Vanilla-Scented Candles are Killing His Wife

This is gonna be pretty long.

Some backstory: Before being diagnosed with asthma, I used to smoke weed (state where weed is legal for personal use). I would do this outside, for obvious reasons. Although this doesn't violate the terms of my lease, my upstairs neighbor insisted that he wanted to keep his screen door open all day, so I needed to quit smoking outside because he has a baby grandson who comes over sometimes. My neighbor told me to go into some guy's backyard and smoke. I didn't think that was a great idea, but I understood where my neighbor was coming from, so I switched to smoking in my car. Coincidentally, around the same time, I developed asthma symptoms and stopped smoking entirely, opting instead to take edibles.

I have smelled the scent of marijuana a few times through the vents, but it's very vague and I never thought anything of it. That first situation with my neighbor happened around a year and a half ago, but just a few weeks back, he put up a sign that said, "STOP SMOKING POT. YOU ARE AFFECTING OTHERS' HEALTH CONDITIONS." I kinda laughed that off, knowing that he for sure thought it was me, but it wasn't. Around that time, the apartment manager sent out an email saying to make sure to smoke weed outside.

Anyway, he knocked on my door about a week ago while I was home alone and my boyfriend was at work. This was pretty late, so I opted not to answer, and he walked away. Keep in mind (obviously) no weed had been smoked by me, lol.

Yesterday night, he showed up again, and similar story, I was home alone, it was late and I tried to ignore him (he's done other stuff that makes him seem not the most stable but tit isn't relevant here) similarly, of course, still not smoking weed, but he kept banging harder and harder and harder, for longer and longer and longer until I finally opened the door, pretty ticked off at this point. Some variation of the following conversation ensued.

Neighbor: PLEASE-STOP SMOKING WEED INSIDE!!!!

Me: I'm not, I have asthma. I don't smoke weed anymore.

Neighbor: Okay, well SOMEONE is, and my wife has AFIB, so smelling weed will kill her.

Me: Wow, I've never heard of someone dying by just smelling the scent of marijuana. That must be a rough life. Sorry about that.

Neighbor: Please just go into that other guy's backyard to smoke.

Me: I will show you my inhaler if it'll help prove that I'm not the one doing it. *goes to grab inhaler*

Neighbor: No, no, no. The other neighbors say it isn't them, though.

Me: Yeah, I bet. I've smelled it too a few times, super faintly, but I swear on my life, it isn't me.

Neighbor: Hmph. Are you using candles inside?

Me: No, that also aggravates my asthma.

Neighbor: Hmmm. Those also kill my wife if she smells them through the vents. Especially those vanilla ones.

Me: Wow. That sounds like a horrible medical condition.

Neighbor: If you see the person who's doing this, let them know that they are ACTIVELY KILLING MY WIFE. *still obviously does not believe a word that I'm saying*

Me: Uh, okay, sure.

And then he reluctantly left.