They were fined on what they were caught, not on what they did. They seem to keep repeating such schemes time and time again. Unless execs are jailed, this is cost of doing business. At some point an exec either said, "let's do it," or closed his eyes and ears.
This time the fine was calculated based on the recovery rates from the French people retrieving their money back to France (the law changed drastically in France and to avoid jail time, many people brought back money from Switzerland). This gave the government statistics to evaluate the effective fraud and thus calculate the corresponding fine.
Of course, over the years, we can be pretty sure that UBS made more money out of these schemes than the fine and they are most likely having such a scheme running right now which may be discovered in 10 years if we are lucky.
