The reasons Blanc gives are much more complicated than a simple question of, was he taking money or not - in fact, it is precisely Barère's actions, as well as his connections with a network of English secret agents, that are called into question here. I'm afraid I can't summarize them here, because, to be fair, it's not a question that can be summed up in a sentence or two. You don't have to agree with Blanc's argument, but I would suggest reading it before dismissing it.