Irrelevant. The root cause was the fraudster or the committer of the mistake. But for his account being incorrectly debited in the first place, he wouldn't be a victim at all.
You clearly don't use the same definition of direct as I do. I probably should never have mentioned directness (in fact I'm not sure I was first to do so) since it really matterns not a jot whether any victim is direct or indirect, what matters is that there is a victim, or more than one.
To my mind the direct victim is not the one who suffers the ultimate loss, but the one who suffers the first loss. That is the cardholder. He may, through some action, offload the loss of money to retailer/bank, but that offloading is a redirection, an indirection, and that makes the retailer/bank indirect victims. Even if he thus manages to avert loss of money, he remains a victim in terms of loss of time and bliss, and that is clearly direct too.
Not clear. Depends on definition of direct. See above.
I thought it was, why else would he (see subject line) accuse them of assisting fraudsters?
Luckily I've so far escaped being a victim of such a mistake never mind such fraud. So obviously I have no evidence, but I thought it was generally accepted that departments which handle such complaints did in fact usually first try to fob you off. I'm sure somebody mentioned it on this very thread.