Well the text I posted was from the journalistic article. The scientific paper indeed says they let the animal recover from the amputated leg. However, as you say, I now agree that it is not clear what they mean with “recovery”.

> We amputated the right middle leg of wild-type Canton S flies, allowed the animals to recover, and then evaluated escape responses at different temperatures. While intact animals displayed minimal escape attempts when exposed to a 38°C surface, after amputation, flies showed significantly more escape behaviors.