I can put the blame to your customers. If I make a contract with a bank they are responsible for my money. I don’t care about their choice of infrastructure. They are responsible for this. They have to be sued for this. Same for hospitals. Same for everyone else. Why should they be exempt from punishment for not providing the one service they were trusted to provide? Am I expected to feel for them because they made the “sensible choice” of employing the cheapest tools?
This was a business decision to trust someone external. It should not be tolerated that they point their fingers elsewhere.