Apple pay - failed message but paid anyway

Has anyone had this happen? I recently tried to make a donation at a site that offered apple pay as an option. The circle spun around for a while and came up with the “transaction couldn’t be completed” message.

I checked my apple pay settings and tried it again and it worked as expected. So far, so good.

Later when I checked my email there were two receipts for the donation with different transaction numbers. It appears that the first transaction went through in spite of the failure message.

Am I missing something here?