Biscuit crumbs fell carelessly down his shirtfront.

[tree123]

‘You know our position on corruption,’ the Minister had insisted casually, reaching for a biscuit.

‘Ah, yes, you mean the corruption that permits rich businessmen to buy votes in the British Parliament and in every corner of the US Congress?’ Chombo had replied softly. For a big man he could speak very softly, which somehow made the words shout all the more loudly.

‘I’m not interested in an empty debate, Mr Chombo. You know what I mean. Your country has a dark past in such matters.’ Then the Englishman had hesitated. Even Micklethwaite had to admit it was a clumsy turn of phrase. Biscuit crumbs fell carelessly down his shirtfront.

From Old Enemies By Dobbs

Do you have any idea why Dobbs described about biscuit twice?

Edit:
When I read the words again. I think the key word is 'carelessly'.

Does the last sentence in red refer to Micklethwaite realised his remarks were offensive, but he didn't as care what his listener would think about his remarks as he didn't care the biscuit crumbs fell CARELESSLY down his shirtfront.

Am I correct?

 

[emsr2d2]

I think both mentions of the word are used to indicate that the speaker was perhaps not treating the matter as seriously as he should. People talking about a very serious matter should not also be eating (a biscuit or anything else) while talking. It suggests a level of discourtesy.

 

[Tarheel]

From Old Enemies By Dobbs

Do you have any idea why Dobbs mentioned the biscuit twice?

I don't know, but that biscuit was quite careless.
;-)