He later changed his mind about fleeing as the accident with the Mini was likely caught on CCTV footage. Mr Kittisak last Sunday returned to the police station to file a report on the physical assault.
Mr Kittisak's lawyer, Songkan Atchariyasap, confirmed yesterday that doctors said his client needs as many as 30 days of treatment.
The attacker could face a jail term of up to 10 years in this case, said Mr Songkan, who is also the chairman of the Network Against Acts that Destroy the Kingdom, Religion and Monarchy.
Meanwhile, Yannawa police investigator Thawip Sutthi yesterday took Mr Kittisak to the scene where the attack took place to gather information about the incident.
Mr Kittisak insisted Mr Witawat shoved him in the back while he was being punched by Akanat.
During the assault, a 51-year-old construction contractor who witnessed the attack, told police the motorcyclist did not fight back during the encounter.