"and I had his deposit to fall back on that airbnb are holding on my behalf."
You've been an Airbnb for 10 years and you didn't know that Airbnb most definitely does not hold a security deposit from guests? It's only a bogus security deposit- something the guest could be charged if they do damage, but which all they really need to do is refuse to pay.
Sorry this happened to you, but A. you should have charged him through Airbnb, not made arrangements off-site or trusted him to pay up once he'd left . B. it's not a good idea to deal with things like this by calling or texting a guest- if you keep the communication on the Airbnb messaging system, there will be a record of what transpired.
Also, it sounds like this was simply a accident, not willful damage. What exactly needed to be paid for? The picture frame broke? The glass? Unless guests break some costly item, or break things intentionally or because they were being wild and uncaring, it's better to set aside a few bucks from each booking and build up a fund to cover replacing things broken by accident, rather than trying to charge a guest.