My assumption is that the key difference is between routine and extra-ordinary activities. The following is all speculative, not based on anything concrete in the book.
IOI is willing to break laws and kill people in the hunt for the Egg. The number of times it does this and the number of people watching for them doing it is low and zero respectively.
The Genetic Privacy Act is a piece of bureaucratic legislation, which while it protects individuals is only useful for companies if done on mass. Just like today, companies don't use the browsing data of a single individual to target advertising, they use composites built from huge data sets. So in order to get anything out of the breaking the GPA, they'd have to do it a lot and make the result data available to a large number of people/teams within the company to get anything out of it. And while there are government agencies looking for companies breaking these laws, there are also potentially large numbers of individuals and NGOs doing the same, just like they do over privacy violations today. So, IOI would have to do it a lot, and there are a lot of people watching.
This makes breaking the GPA a much higher risk than the odd murder, which is why IOI don't do it.