I feel myself get internally angry at scientific inaccuracies I found in a tumblr post about the plague
What is innacurate about the tumblr post you read?
It is fairly inaccurate, the writer isn't a historian, they've never been to a plague museum and I doubt they have any credentials in the subject
I like that your critical about scientific claims because there is a lot of misinformation on the internet.  There are most likely some inaccuracies, however you should do more research and be more specific before you make those types of claims.
Anyone can say that without proof. Doesn't mean much.
I think you could invite the other person to learn about the subject with you if you feel so strongly. I think we might actually know since a lot of history back then was superstitious and inaccurate to begin with.