One party paid the money for reservation, other party is ignorant of the rules. Situation is pretty clear to me, but I'm programmer and have trouble noticing subtle unwritten social rules.
You can’t fault the Dropbox people there for making a reservation and expecting that it would be valid. They’re a bit clueless in how they respond, though, not realizing that those rules are clashing with the unofficial social dynamics happening there.
(Semi-related : That’s why we might feel that banks are assholes for foreclosing houses that belong to deployed soldiers. Legally they can do it, but it sounds like it’s the shittiest application of the law.)