Jackson lost her job as a result of the Macquarie buyout collapse; the smaller fine than BA is due to involvement in the cargo operation only, with the max US fine being 10% of worldwide revenue (relating to that cargo operation).
The profit is not considered by the DoJ in determining the fine, and considering that the BA "cartel" involved no more than a handful of people, it is hardly likely or realistic that it was orchestrated by, or known to Dixon at any point in time.
Why would the shareholders want to get rid of the man who has driven the stock price up from $2.96 to $5.81 in 18 months?