The Supreme Court, the highest court in our country, uses three criteria for reckless driving.
1. A suspect must have behaved extremely carelessly.
2. By his behavior he must have caused a very serious danger.
3. He must have been, or should have been, aware of this.
For reckless driving, the maximum penalty for a fatal accident is higher than for lower categories of guilt: 6 years in prison instead of 3 years.
Both maximum limits can be increased by half by the judge if there is extremely dangerous driving behavior (for example a wild chase and/or excessive drinking). For example, the 6-year prison sentence for reckless driving can be increased to 9 years.
https://www.rechtspraak.nl/Themas/verkeersmisbedrijven/Paginas/Roekeloos-rijder-en-de-wet.aspx