Suggestions? AirBnB sided with host to replace sofa for coffee ring I didn’t cause

I’ve stayed at dozens of AirBnBs in the US, Europe and South America, but never encountered a host complaint for damages. Yet a two week after my monthlong stay ended, the host submitted a claim for damages claiming I caused a “burn” (really what seems to be a coffee ring stain) on the wooden arm of a sofa bed, and asked for me to replace the entire piece of furniture.

I didn’t cause the stain, and didn’t report it when I checked in because a minor, cosmetic detail like that didn’t register as something I could even be held responsible for. But despite the fact that I have a picture from 24 hours after check-in showing the stain the same condition the host reported it, AirBnB sided with them (even after I appealed).

It feels unfair to be held responsible for damage I didn’t cause, and also quite unreasonable to be asked to replace an entire piece of furniture for such minor damage.

Two questions for the community: is there any other recourse I have, now that my final appeal has been denied? And how can I prevent this in the future?