I don't think the "natural properties" of a career or industry will be enough to be lowest. I think an industry or career with high oversight from many individuals and regulators. Likely something that has fucked up before, and massively.

Slot machine programmer.

• regulated industry
• work can be checked many times
• customers (casinos) don't want to be fucked
• gamblers don't want to be fucked
• loads of money to be made doing things well
• lots of scary people willing to drop you in a hole