Vera Mol, a 17-year-old from the Netherlands, was standing on a 130-foot-high bridge on Spain’s northern coast, bracing for her first bungee jump.

It was 8:30 p.m., and she was the last in a group of 13 teenagers to go, when the instructor gave a command.

“No jump, it’s important, no jump,” he said in English, according to court documents. But Ms. Mol, apparently misunderstanding his pronunciation, heard, “Now jump.” She threw herself from the ledge — and plunged to her death. The harness she was wearing had not yet been secured to the bridge.

This month, an appeals court in Cantabria, in northern Spain, upheld a ruling that the instructor for Aqua21 Aventura, the company that had organized the bungee jump in August 2015, could face criminal charges, including accidental homicide, should prosecutors decide to proceed with the case.