Wich they weren't any more and hadn't been for years. And even if they knew about his influence peddling. (Something that isn't illegal by the way, just unethical). It is insanity to believe that they would have known offhand what specific information was on his laptop. In order to know what is on a laptop a fairly invasive search has to be done on it. The type of search that would require an actual warrant, which would require actual convincing reason to believe evidence of a crime could be found on that laptop, which as I said influence peddling is not.
They had the information in the New York post article to go on. The very... call it unlikely way they came in possession of that laptop. Previous Russian actions in influencing elections, and their own judgement. I don't think it a stretch to conclude that the information on it is probably fake going by that information.