Ponciano borrowed Ruben's gun, saying that he would use it to kill Freddie. Because Ruben also resented Freddie, he readily lent his gun, but told Ponciano: "O, pagkabaril mo kay Freddie, isauli mo kaagad, ha." Later, Ponciano killed Freddie, but used a knife because he did not want Freddie's neighbors to hear the gunshot.

(a) What, if any, is the liability of Ruben? Explain.
(b) Would your answer be the same if, instead of Freddie, it was Manuel, a relative of Ruben, who was killed by Ponciano using Ruben's gun? Explain. (2009 BAR)