I think it's a bad idea to call out inspectors--they are usually better at providing you with plenty of legalese and unnecessary (expensive) requirements than at actually being interested in your welfare.
From a biologist perspective, I would be far less worried about bacteria than about chemicals. If your leach field had been functioning normally, the "leak" is likely to have occurred because the septic tank overflowed (too full). Bacteria and other natural flora and fauna should quickly compost the sewage unless it was treated with antibiotic chemicals like bleach, pipe cleaners (Drano), or whatever other harsh chemicals might have been dumped down the drain. It's a big no-no to use chemicals on a system that depends on natural decay to neutralize the wastes.
If it's been over a month, nature should have handled whatever was natural, and I would think it was quite safe for your chickens. It might not be safe if the area had become, and still is, swampy. If it is dry, the air (oxygen) is a natural disinfectant.
In cases like this, many people's worries are based more on the "gross" factor (it's just the thought of something that is bothersome). Biologists know, for example, that there are more dangerous bacteria harbored in the average kitchen sink than in the average (flush) toilet--but most people would tend to think opposite to reality, just because...well...they'reYnot thinking in terms of biology, I suppose.