Can collection agencies get on your credit report without proof that you owes money to the creditor who claims you do?

The answer to this question hinges on your understanding of the Word "proof". A consumers' standard of proof is not the same as a collection agency, or the credit bureaus. Their standards of proof, or verification, would fall far short of your definition. Case law has upheld their version. Having your identifying data, like name, address and social security number, and a ledger sheet of the account with balance and interest accrued is what is accepted in court as proof. Consumers need to be aware that at no time will business or legal entities involve themselves in the nature of their dispute. When the issue is "proof", you need to address that will the "person that claims...".