His girlfriend alleges that Omenihu pushed her to the ground during an argument. San Francisco 49ers defensive end Charles Omenihu was arrested Monday and booked in the Santa Clara County jail on suspicion of misdemeanor domestic assault. He since has posted bail and been released. “We are aware of the matter involving Charles Omenihu and are in the process of gathering further information,” the 49ers said in a written statement provided to the media. Police reportedly were called to Omenihu’s residence in San Jose at 4:39 p.m. on Monday. His girlfriend alleges that Omenihu pushed her to the ground during…