What exactly happened that led to the IndiGo crisis?

To make air travel safer, pilots were demanding more rest hours. Therefore, DGCA issued new rules, said aviation expert Subhash Goyal. "Airlines were instructed over a year ago to recruit more pilots...However, IndiGo...increased...flights without increasing [staff]," he added. "When government wanted to enforce...policy deadline, IndiGo...grounded...flights...It created complete chaos," he said.