If it's fraud it's on the part of the mother (usually) - the state just wants a clean database to avoid complications; it doesn't actually care about truth.
It's similar to how the justice system doesn't really care about justice, it cares about detailed and systematic applications of the laws, which sometimes coincides.
"the state just wants a clean database to avoid complications; it doesn't actually care about truth."
What it actually cares about is not having to pay CHIP, etc. Having a man who isn't the biological father paying for stuff means the state doesn't have to pay for services. They don't care at all beyond that.
It's similar to how the justice system doesn't really care about justice, it cares about detailed and systematic applications of the laws, which sometimes coincides.