Why is there a black wire by the neutral wire? Is this wrong?

A black wire should never be placed on a neutral bar because, according to the electrical code, black wires are designated as "hot" wires, meaning they carry live electricity, while the neutral bar is meant for neutral wires (typically white) which complete the circuit by returning electricity to the source; putting a black wire on the neutral bar could create a dangerous situation by confusing the wiring and potentially causing a shock hazard.