A police officer was reassigned after videotapes showed him thrusting his baton into a crowd demonstrating outside a hotel where Vice President George Bush was holding a fund-raiser, San Francisco Mayor Art Agnos said Saturday. Dolores Huerta, a United Farm Workers vice president who was distributing information about a table grape boycott, was injured during the demonstration Wednesday. Agnos said Huerta was clearly visible in the group seen on the videotape. Huerta suffered two broken ribs and a ruptured spleen. Agnos said he, Police Chief Frank Jordan and other top police officials reviewed videotapes of the protest provided by television station KRON before deciding to reassign officer Francis Achim to administrative duty.