Looks like affiliates are an extension of the blackhat
SEO, in effect, free advertising, and affiliates do all the hard work and get hit with a raft of questionable deductions so they do not receive what they expect.
They are having a laugh at your expense when suggesting it is somehow "your fault" that they were able to click through on your banner. Did YOU single handedly design the HTML protocols?, did you program Windows? Are you offering your own web browser for download? if your answers are in the negative, then is isn't "your fault".
THEY seem happy for this player to continue their "fraud", so it can't be that bad, and if Full Tilt were REALLY being scammed out of 5x what they deduct from your account this player would have been given the size 12 boot ages ago.
Maybe this player IS running bots, but is generating so much rake that Full Tilt can still make a profit even though other players are being played by a potential bot.
I have seen this specific allegation elsewhere, that less reputable sites will turn a "blind eye" to small time bot operations provided it does not have a negative effect on the site's profits from rake (perhaps by driving other players away).