LONDON — Two of the most senior figures at the BBC said Tuesday that there had been ‘‘basic’’ and ‘‘elementary’’ failures of the organization’s journalism when it wrongly implicated a former Conservative Party politician in sexual abuse, compounding a scandal that cost the BBC’s director general his job and plunged the organization deeper into crisis.

But, addressing a parliamentary panel, one of them, Chris Patten, the head of the supervisory BBC Trust, offered an unusually insistent defense of the former director general, George Entwistle, whom he had hired, and who had been labeled hapless and bumbling by many politicians and newspaper columnists before and after his resignation on Nov. 10.