Sentence:  [Professor Fearnley:] If I can perhaps be a little unkind about my profession — which is fair enough I suppose — I think the accountancy profession, along with other professions, <WSD>loses the plot</WSD> from time to time and has to be pulled back from what it was doing before. 
Meaning of the word marked with <WSD> tags:  To lose sight of an important objective or principle; to act contrarily to one's own interests through concentrating on relatively unimportant matters.