yes it might be but it is not the only possibility i am jsut trying to say that i do not think it is regulus how would he have done it alone dumby is like the greatest wizard ever and he needed help how would regulus do it alone and if he did do it with someone else they would want to be mentioned if ur gonna do something to spite voldy ur not gonna lie he would know it so there is no point in lieing i dont know about the rita idea cuz shes not that bright at all but sure who knows we will not know til the 7th book comes out