PROOF is not required in a libel case, merely evidence and an absence of malice. There was and is some strong evidence, but AT does not have the resources to fight a multi$Billion lawfare bully. So they turned tail.
Jimrob fought LA Times and as a result we have this ridiculous list of sources we have to excerpt. But that was just a result of a legal compromise, not a finding in law.
AT could have fought a little bit harder for some kind of settlement, like Jimrob did.
I have no doubt if they had actual proof some conservative would have taken this on pro bono. Dominion is not as big as Apple or Facebook so the whole David vs Goliath thing just doesn't apply here. There is a reason AT backed away and it's because they knew they would lose. As I said, Dominion obviously not afraid of discovery
But that was just a result of a legal compromise, not a finding in law.