I think the "player" should be changed to "target".

            if (target.IsAdmin)
            {
                target.SendConsoleCommand("ddraw.text", 0.1f, color, player.transform.position + new Vector3(0, textHeight, 0), message);
            }
            else
            {
                target.SetPlayerFlag(BasePlayer.PlayerFlags.IsAdmin, true);
                target.SendNetworkUpdateImmediate();
                target.SendConsoleCommand("ddraw.text", 0.1f, color, player.transform.position + new Vector3(0, textHeight, 0), message);
                target.SetPlayerFlag(BasePlayer.PlayerFlags.IsAdmin, false);
                target.SendNetworkUpdateImmediate();
            }​