Buffett admits to employee 'mistake' in share-trading scandal

Billionaire US investor Warren Buffett has admitted he made a “big mistake” in not grilling a top executive allegedly involved in a share-trading scandal.

The investment guru told around 40,000 shareholders gathered at the annual meeting of his conglomerate Berkshire Hathaway he should have questioned David Sokol more thoroughly over why he held shares in a firm Berkshire was looking at acquiring.