Poultry Talk Ontario (pto.ca)

Hi everyone, just processed 62 meat birds today - I'm exhausted - and 1 of them, and only one, had yellow spots on the liver and was rather scrawny. Any thoughts?

Were the spots circular or irregular? Flat or raised?

I’m going to say flat and irregular

Ulcerative enteritis?

Yes to the above especially if the were through the intestinal tract as well.

Almost any common bacteria, virus or parasite can cause the liver damage symptoms you describe.
Most are contagious or so prevalent in the environment that there's an outbreak. Since it was only one bird, I'm inclined to think either he had a genetic weakness to common things like e. coli or Coccidia parasites, or, he ate large amounts something nasty, like spoiled meat, or a little of both.

SAFE TO eat?

Yep, if thoroughly cooked

Personally I wouldn't eat it if there is liver involvement.