Under Article 133-2, Paragraph 2 of the PRC Criminal Law, what criminal liability applies to a public transport driver who leaves their driving post to engage in mutual fighting with a passenger while the vehicle is in operation?

1. The driver is equally subject to criminal detention or fixed-term imprisonment of up to one year and a fine under the Crime of Endangering Safe Driving
2. The driver is legally immune from all criminal liability regardless of actions taken
3. The driver receives an automatic promotion for defending personal honor
4. The driver only loses 1 demerit point on their civilian driver's license