Hi Paul
Mastercard and Visa debit cards have the same consumer protections as the equivalent credit cards i.e. you can dispute any transaction where you believe the merchant hasnt fulfilled their obligations.
So the short answer is yes.
Im not 100% sure what you're getting at though - have you been wrongly accused in the past?
With DEBIT cards, there is NO law of joint liability
The rules in Australia are the same for both credit and debit cards.
I know this because I once had cause to dispute a transaction with an online merchant in the US (not a casino ) and it was all handled as if it were a credit card transaction. Over here we have 180 days to lodge a dispute.
Sounds like MC Debit cardholders in the UK are being screwed!