You can sue them but it is a long process and you won't get U.S.-style amounts for payouts. That's if you can get that far. The staff cover for each other and use processes like the Ombudsman to delay and obfuscate. Also, the UK is not a litigious culture and my mother and other family members simply didn't want to go through more trouble.

You can't complain about not getting compensation if you didn't go through the process that would get you compensation.

Jut out of interest, do you know anyone who has claimed, and won, any decent amount of damages from the NHS?