That seems like the most reasonable explanation. Yes, asking for cash upon arrival is super sketchy, the review was probably fair, but in my experience, getting a negative review removed from a completed Airbnb transaction requires both parties to consent.
My experience, for reference: A couple stayed on our second floor, and left dozens of snotty tissues all around the apartment, put recylables in the trash, and just kind of left the place a mess. No permanent damage, and otherwise, were perfectly fine guests. I gave them five stars for everything but cleanliness, and this man LOST HIS MIND about this new stain on his ratings. Claimed he didn't do anything, reacted poorly when I added pictures to the thread, made excuses, begged for me to change the review (I couldn't!), and eventually accused me of being homophobic (?!?!). Thing is, he lived an Amtrak ride away, and was acting irrational enough that I was worried about further escalation, so eventually I contacted Airbnb and asked them to take my review down.