You both have been lucky in finding a peer that let you alter the agreed upon payment method, as instead they could very well have opened mediation on you, and the mediator, no matter how understanding they would have been, would have had to follow the Bisq platform rules, and impose a penalty on you for having used a different payment method.
The best practice in these cases, unless you have means of trusting the peer, because maybe they are people you already traded with in the past, is to open mediation, explain everything in detail, attaching proofs of what happened, and then the mediators themselves will suggest to use a different payment method if both peers agree to it. You would be playing by the rules this way.