Would provisional credit apply if an accountholder, not the card holder, filed a unauthorized debit card dispute? The regulation states "consumer" which does state accountholder or cardholder. In my opinion, if accountholder provided written notification of an unauthorized transaction provisional credit would apply. Thoughts?

Since even notice by a third party is valid, I am not sure how you could deny rights to one of the other accountholders.

2. Notice by third party. Notice to a financial institution by a person acting on the consumer's behalf is considered valid under this section. For example, if a consumer is hospitalized and unable to report the loss or theft of an access device, notice is considered given when someone acting on the consumer's behalf notifies the bank of the loss or theft. A financial institution may require appropriate documentation from the person representing the consumer to establish that the person is acting on the consumer's behalf.