The story happened in Morocco. The buyer probably took advantage of the fact that the young french seller was unaware of the regulations to file a complaint after the btc dropped.
Although at first she obviously accepted.

Virtual currency transactions are strictly forbidden in the Morocco, and officially constitute a breach of the country's foreign exchange regulations. Morocco's foreign exchange regulations clearly stipulate that resident Moroccans may only have foreign accounts under certain conditions (i.e., being an exporter of goods or services). Any breach of these rules is punishable by 5 years' imprisonment and a fine of between 500 and 20,000 dirhams.