" ... He went on and said that the Guardian news paper could have apostates working for them for all we know. I said, Oh, I never thought of that..."
That really is quite a statement. It is a good reason for you to examine further if the Guardian may have apostates working for it. Being as the Guardian is one of the sources of information you rely on to keep abreast with social events you will have to be careful but not necessarily reject it outright. You may want to ask the elder who suggested this to instruct you on how you will be able to determine if apostates are actually working for the paper. Tell him you are eager to examine all your sources of information and you will use his instructions to weed out any sources that are apostate. Perhaps you could ask if you could repeat his statement to other ears. It must have some truth to it or why would he utter the statement? You would want to assure him that he could not be guilty of slander if there is a basis of truth to his statement and not just something that he thought of at the moment.