If trader A fails to confirm the receipt of a national currency transfer within the allotted time (e.g. six days for SEPA, four days for Zelle, one day for altcoins, etc.), a button to contact the arbitrator will appear to both traders. Trader B will then be able to submit evidence to the arbitrator that he did, in fact, send the national currency. Alternatively, if trader B never sent the national currency, trader A will be able to submit evidence to the arbitrator that the funds were never received. Submitted evidence should be cryptographically secure using either PageSigner or digitally-signed bank statements. If these methods fail, more traditional routes of discovery can be deployed.
From our experience the huge majority of cases are caused not by any malicious intention but by problems like bugs, bank issues, usability, etc.
The arbitrator will side with buyer or seller and sign the 2-of-3 multisignature address in favor of the appropriate party.