Bosses at Cardiff and Vale University Health Board revealed the full extent of their findings as the partner of one of the eight patients whose death was "unavoidable", began legal action to find out exactly what happened.
Martyn Rogers, 66, of Newport, died of blood poisoning and acute liver failure in summer 2012 at University Hospital Wales.
His death on July 25 came one week after surgeon Dr Berry carried out the vital operation to remove tumours from his liver.
Lawyers acting for Maria Davies, his partner of 40 years,have launched their own investigation into what happened in the case of Mr Rogers.
More top news
A headteacher has reportedly warned "snowplough" parents are so over-protective that their children end up unable to deal with failure.
The largest horse chestnut tree in the country declared as the 300-year-old specimen at the estate where PM Benjamin Disraeli once lived.
The fanfare and fireworks at Tattersalls in Newmarket on Friday failed to materialise as three Frankel foals met with differing fortunes