Technically a payment terminal can go into island mode and take offline credit card transactions and post them later. PIN can be verified against the card.
Depends if the retailer wants to take the chance of all that.
Having worked with some of these retail systems, yes, it depends on how they are configured.
There are stores in many places in the country with sporadic internet or where outages are not uncommon, and where you would want to configure the terminals to still work while offline. In these cases, the payment terminals can be configured to take offline transactions, and they are stored locally on the lane or a server located in the store until a connection to the internet is re-established.
Depends if the retailer wants to take the chance of all that.